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Fig. 1: Power, Ground, Antenna and Data Communication |
2016-2018
Chevrolet Volt
Service Manual
SPECIFICATIONS
FASTENER SPECIFICATIONS
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Reusable Threaded Fastener Tightening Specifications | |||||||||||||||||||||||||
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SCHEMATIC WIRING DIAGRAMS
RADIO/NAVIGATION SYSTEM WIRING SCHEMATICS
Power, Ground, Antenna and Data Communication
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Fig. 1: Power, Ground, Antenna and Data Communication |
Amplifier Inputs (UQA)
Fig. 2: Amplifier Inputs (UQA)
Courtesy of GENERAL MOTORS COMPANY
Auxiliary Audio Input
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Fig. 3: Auxiliary Audio Input Courtesy of GENERAL MOTORS COMPANY |
Info Display
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Fig. 4: Info Display Courtesy of GENERAL MOTORS COMPANY |
Speakers (UQA)
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Fig. 5: Speakers (UQA) Courtesy of GENERAL MOTORS COMPANY |
Speakers (UZ6)
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Fig. 6: Speakers (UZ6) Courtesy of GENERAL MOTORS COMPANY |
ONSTAR/TELEMATICS WIRING SCHEMATICS
OnStar Schematics
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Fig. 7: OnStar Schematics Courtesy of GENERAL MOTORS COMPANY |
CELLULAR TELEPHONE WIRING SCHEMATICS
Cellular Telephone Microphone (-UE1)
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Fig. 8: Cellular Telephone Microphone (-UE1) |
DIAGNOSTIC INFORMATION AND PROCEDURES
DTC B0997: AUXILIARY ELECTRONIC CONTROL UNIT PERFORMANCE
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Auxiliary Electronic Control Unit Performance Incorrect Component Installed
Auxiliary Electronic Control Unit Performance Internal Electronic Failure
Circuit/System Description
The info display module monitors itself for internal failures and reports its condition to the Human Machine
Interface Control Module when requested. The info display also reports electronic identification information when
requested.
Conditions for Running DTC
• Ignition is ON or in the ACC position
• The system voltage is 9-16 V
• DTC B101E is not set as current in the Human Machine Interface Control Module
• The test is run once during Human Machine Interface Control Module wake up
Conditions for Setting the DTC
The Info Display Module has reported identification information that differs from the information calibrated in the
Human Machine Interface Control Module.
The Info Display Module reports an internal malfunction.
Action Taken When DTC Sets
The Human Machine Interface Control Module will set the DTC and the Info Display Module will have limited or no
functionality.
Conditions for Clearing the DTC
The Human Machine Interface Control Module detects a compatible Info Display Module with no internal
malfunctions reported.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Vehicle in Service Mode, Infotainment system ON.
2. Verify DTC B101E is not set
• If DTC B101E is set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
• If DTC B101E is not set
3. Verify DTC B0997 is not set
Replace the P17 Info Display Module.
4. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Radio Control Assembly Replacement
DTC B1024: CIRCUIT BOARD TEMPERATURE SENSOR ABOVE MAXIMUM THRESHOLD (AUDIO
AMPLIFIER)
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Circuit Board Temperature Sensor Above Maximum Threshold
Circuit/System Description
The audio amplifier monitors the internal circuitry for excessive temperature. When the amplifier senses an internal
circuitry temperature greater than 95A°C (203A°F), the amplifier will set DTC B1024 11 and shut down until the
internal circuitry cools below 90A°C (194A°F). No external circuit diagnosis is involved.
Conditions for Running the DTC
• Radio ON.
• Battery voltage must be between 9-16 volts.
Conditions for Setting the DTC
The audio amplifier detects an over-heat condition greater than 95A°C (203A°F) of the internal amplifier circuitry.
Action Taken When the DTC Sets
The audio amplifier will shut down and all speakers will be inoperative.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
Extended use or extremely high volume especially in warm weather conditions may cause this DTC to set. Under
these conditions it may be normal for this DTC to set to prevent permanent damage to the audio amplifier circuitry.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE: Allow the vehicle cabin to cool if the temperature inside the vehicle is excessive
before proceeding with this diagnostic procedure.
1. Verify the DTC sets outside of the Conditions for Running and Setting. Since most occurrences of this DTC
are caused by extreme vehicle cabin temperatures due to ambient conditions, review with the customer the
conditions under which the DTC set.
• If the DTC sets within the Conditions for Running and Setting.
The system is operating as designed, All OK.
2. Using the scan tool, clear the DTC.
3. Verify the DTC does not set while operating the infotainment system under the conditions the customer
experienced the concern.
Replace the T3 Audio Amplifier
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Refer to Control Module References for audio amplifier replacement, setup, and programming
DTC B1024: CIRCUIT BOARD TEMPERATURE SENSOR THRESHOLD
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Circuit Board Temperature Sensor Below Minimum Threshold
Circuit Board Temperature Sensor Above Maximum Threshold
Circuit/System Description
The human machine interface control module monitors the internal circuitry for excessive temperature. When a
temperature outside of the range is detected, the module sets the DTC and limits its operation to avoid damage.
Conditions for Running the DTC
• Ignition On/Vehicle in Service Mode.
• The system voltage is 9-16 V
• The test is run once per second when the infotainment system is operating
Conditions for Setting the DTC
The module senses an internal temperature less than -40A°C (-40A°F).
The module senses an internal temperature greater than 69A°C (156A°F).
Action Taken When the DTC Sets
• The human machine interface control module sets the DTC.
• A message is displayed indicating that the system performance is being impacted by the excessive temperature
condition.
• The module stops communicating on the MOST Bus network, but does not interrupt communication on the
network.
• The infotainment system and the Info Display Module will have limited or no functionality.
• Components or other subsystems that interface with the infotainment system may have limited or no
functionality.
Conditions for Clearing the DTC
• The internal temperature is between -40A°C (-40A°F) and 69A°C (156A°F).
• A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
Under certain conditions it may be normal for this DTC to set to prevent permanent damage to the module.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE: Allow the vehicle cabin to cool if the temperature inside the vehicle is excessive
before proceeding with this diagnostic procedure.
1. Verify the DTC sets outside of the Conditions for Running and Setting. Since most occurrences of this DTC
are caused by extreme vehicle cabin temperatures due to ambient conditions, review with the customer the
conditions under which the DTC set.
The system is operating as designed, All OK.
2. Using the scan tool, clear the DTC.
3. Verify the DTC does not set while operating the infotainment system under the conditions the customer
experienced the concern.
Replace the K74 Human Machine Interface Control Module
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for human machine interface control module replacement, programming, and
setup.
DTC B1025-B1135: AUDIO OUTPUT CIRCUITS
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Audio Output 1 Circuit
Audio Output 2 Circuit
Audio Output 3 Circuit
Audio Output 5 Circuit
Audio Output 6 Circuit
DTC B1085
Audio Output 7 Circuit
For symptom byte information refer to Symptom Byte List .
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Diagnostic Fault Information | |||||||||||||||||||||||||||||||||||
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Circuit/System Description |
The Media Oriented Systems Transport (MOST) is a high-speed multimedia network technology. The serial MOST
bus uses a ring topology and synchronous data communication to transmit audio, video, data and control information
between any devices attached.
The audio amplifier is a participant on the MOST network. The audio amplifier receives audio inputs and control
information from the MOST bus.
Each of the audio output channel circuits (+) and (-), at the audio amplifier have a DC bias voltage that is
approximately one half of the battery voltage. When using a DMM, each of the audio output channel circuits will
measure approximately 6.5 V DC. The audio being played on the system is produced by a varying AC voltage that is
centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move
and produce sound.
Diagnostic Aids
• Improper speaker mounting or loose trim may cause an audible buzz or distortion. Inspect the appropriate
speaker and the surrounding interior trim for proper and secure mounting.
The EL-50334-6 Audio System Diagnostic CD contains audio tracks that can be used to duplicate and isolate
such concerns. Tracks 11 and 12 contain audio sweep tones for testing for speaker and grill rattles.
If the speaker or surrounding interior trim is found to be loose or improperly secured, correctly secure the item.
• The test tones on the CD may be copied to a USB drive or other device to use during testing.
• Some audio output circuits are connected to more than one speaker, dependant on vehicle equipment. It may
be necessary to disconnect one or more speakers during testing of some circuits.
Conditions for Running the DTC
NOTE: DTC B1325 must not be set as current for the amplifier to run any of the following
tests.
The test is run initially upon amplifier wake-up, and periodically every one second after amplifier operation begins.
The test is run initially upon amplifier wake-up, and periodically every one second after amplifier operation begins.
The test is run once during amplifier wake-up.
Conditions for Setting the DTC
A short to voltage is detected on the specified (+) or (-) signal circuit
A short to ground is detected on the specified (+) or (-) signal circuit
An open is detected on the specified (+) or (-) signal circuit
Action Taken When the DTC Sets
The amplifier mutes the output channel and no sound is present from the speaker(s) that have a current circuit fault.
Conditions for Clearing the DTC
• The condition for setting the DTC is no longer present.
• A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Circuit Testing
• Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Special Tools
EL-50334-50 USB Cable and Adapter Kit
Circuit/System Verification
1. Ignition ON, infotainment system ON, mute OFF.
2. Verify clear audio is heard from each speaker, adjusting fade and balance controls to test each speaker
individually.
Refer to Circuit/System Testing.
3. All OK.
Circuit/System Testing
NOTE: Some circuits supply audio signals to more than one speaker. It may be
necessary to disconnect all speakers on the affected audio circuit when
performing circuit tests.
1. Ignition OFF, disconnect the harness connector at the appropriate P19 Speaker. Ignition ON, infotainment
system ON, mute OFF.
2. Test for 5 - 7 V between the appropriate signal circuit terminals listed below and ground.
• Front door, tweeter, rear door and subwoofer speakers audio (-) circuit terminal 1
• Front door, tweeter, rear door and subwoofer speakers audio (+) circuit terminal 2
1. Ignition OFF, disconnect the X1 and X2 harness connectors at the T3 Audio Amplifier.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the T3 Audio Amplifier.
1. Ignition OFF, disconnect the X1 and X2 harness connectors at the T3 Audio Amplifier. Ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the T3 Audio Amplifier.
3. Test or replace the P19 Speaker.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for audio amplifier replacement, programming, and setup.
DTC B124B: USB 1 CIRCUIT
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
USB 1 Circuit
For symptom byte information refer to Symptom Byte List .
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Diagnostic Fault Information | |||||||||||||||||||||||||
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Circuit/System Description | |||||||||||||||||||||||||
The infotainment system has a USB port and a Auxiliary Audio Input Jack located in the center console. The
receptacle assembly receives fused battery voltage and ground from the harness to power the internal hub device as
well as providing additional amperage to power USB devices.
The internal hub device interfaces directly with the human machine interface control module via a standard USB
cable. A Mini type USB connector is used to connect the human machine interface control module and the USB
receptacle. Standard USB male to female connections are typically used for connecting USB cables together where
an in-line connection is required. An in-line cable connection is typically found between the console and I/P harness.
When a portable audio playback device is connected to the 3.5 mm (1/8 in.) auxiliary audio input jack an internal
switch opens the detection signal circuit within the hub. The HMI detects the device and AUX becomes available as
an audio source. Audio signals from the device are converted from analog to digital, these signals are then sent to the
HMI from the auxiliary input jack via USB.
USB Port
The USB port allows connectivity to the infotainment system from portable media players or a USB storage device
(memory stick/flash drive). When a device is connected to the USB port, the system detects the device and switches
to USB as the audio source. Once connected, the device can be controlled from the radio controls.
Not all portable media player devices or file types are compatible. Refer to the owner's manual for information on
USB devices, control, and operation.
Conditions for Running the DTC
• Ignition On/Vehicle in Service Mode.
• The system voltage is 9-16 V
• The infotainment system is ON
• The test is run once per second when the infotainment system is operating
Conditions for Setting the DTC
The human machine interface control module detects an excessive current condition on the USB 5 V circuit.
The human machine interface control module does not detect the vehicle hub device.
The human machine interface control module detects an additional hub device attached to the vehicle USB port.
Action Taken When the DTC Sets
The USB port is inoperative while the DTC is current.
Conditions for Clearing the DTC
• The condition for setting the DTC is no longer present.
• A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
• This DTC may be set due to the connection of an incompatible or faulty USB device.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
• EL-50334-20 Multi-Media Interface Tester (MIT)
• EL-50334-50 USB Cable and Adapter Kit
• EL-50334-14 Infotainment Test Cable
Circuit/System Verification
1. Verify DTC B124B is not set. Since occurrences of this DTC can be caused by an incompatible or faulty USB
device, review with the customer the conditions under which their concern occurred.
Refer to Circuit/System Testing.
2. Ignition On/Vehicle in Service Mode. Infotainment system ON.
3. Connect the EL-50334-20 Multi-Media Interface Tester (MIT) to the X83 Auxiliary Audio Input USB port and
select the USB test mode.
4. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the infotainment
system while operating the system to play audio from the test tool.
Refer to Circuit/System Testing
5. Verify the infotainment system can be switched to AUX as the audio source with the EL-50334-20 Multi-
Media Interface Tester (MIT) connected to the auxiliary audio input jack.
• If the infotainment system can not be switched to AUX as the audio source
Refer to Circuit/System Testing
6. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the vehicle
infotainment system while operating the test tool to begin audio playback.
Refer to Circuit/System Testing
7. All OK
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the X83 Auxiliary Audio Input.
2. Test for less than 10 Q between the ground circuit terminal 4 and ground.
• If 10 fi or greater
1. Ignition OFF.
2. Test for less than 2 Q in the ground circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, repair the open/high resistance in the ground connection.
3. Verify that a test lamp illuminates between the B+ circuit terminal 6 and ground.
• If the test lamp does not illuminate
1. Ignition OFF, remove the test lamp.
2. Test for less than 2 Q in the B+ circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If the test lamp illuminates
4. Verify the USB cable is properly connected at all components and in-line connections, and there is no damage
to the cable or connections.
• If connection problems or cable damage is noted.
Perform the appropriate repair or replacement to correct any issues.
5. Connect the X1 harness connector at the X83 Auxiliary Audio Input.
6. Disconnect the vehicle USB cable X3 harness connector at the K74 Human Machine Interface Control Module
and the X83 Auxiliary Audio Input Adapter.
7. Connect the EL-50334-14 Infotainment Test Cable and the EL-50334-2 Type-A Female to Mini-B Male Cable
together. Connect the assembled test cable to the K74 Human Machine Interface Control Module and the X83
Auxiliary Audio Input.
8. Ignition On/Vehicle in Service Mode. Infotainment system ON.
9. Connect the EL-50334-20 Multi-Media Interface Tester (MIT) to the X83 Auxiliary Audio Input USB port and
select the USB test mode.
10. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the infotainment
system while operating the system to play audio from the test tool.
1. Replace the X83 Auxiliary Audio Input Adapter. Connect all harness connectors.
2. Connect the EL-50334-20 Multi-Media Interface Tester (MIT) to the X83 Auxiliary Audio Input USB
port and select the USB test mode.
3. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the
infotainment system while operating the system to play audio from the test tool.
• If audio is not heard from the test tool, replace the K74 Human Machine Interface Control
Module.
11. Connect the EL-50334-20 Multi-Media Interface Tester (MIT) to the X83 Auxiliary Audio Input AUX port
and select the AUX test mode.
12. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the infotainment
system while operating the system to play audio from the test tool.
1. Replace the X83 Auxiliary Audio Input Adapter. Connect all harness connectors.
13. Replace the vehicle USB cable between the K74 Human Machine Interface Control Module and the X83
Auxiliary Audio Input Adapter.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for human machine interface control module replacement,
programming, and setup.
DTC B124F: UNIVERSAL SERIAL BUS (USB) PROGRAMMING
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Universal Serial Bus (USB) Programming
For symptom byte information, refer to Symptom Byte List .
Circuit/System Description
Certain devices in the entertainment system must be programmed with specific software and other information to
operate correctly. This DTC is the result of an unsuccessful USB programming event of the device. The symptom
byte information is for engineering reference only. No external circuit diagnosis is involved
Conditions for Running the DTC
Once upon each USB Programming Event.
Conditions for Setting the DTC
The programming event was incomplete, or completed with errors.
Action Taken When the DTC Sets
The entertainment system has limited or no functionality.
Conditions for Clearing the DTC
The programming event completes successfully.
Circuit/System Verification
1. Vehicle in Service Mode.
2. Verify DTC B124F is not set.
1. Program the device that set the DTC.
2. Verify the DTC does not set.
• If DTC is set, replace the device that set the DTC.
• If the DTC is not set
3. All OK.
3. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for device replacement, programming, and setup.
DTC B125A: ANTENNA SIGNAL CIRCUIT
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Antenna Signal Circuit Short to Ground
Antenna Signal Circuit Open Circuit
Antenna Signal Circuit Short to Battery
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Diagnostic Fault Information | |||||
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Circuit/System Description |
The radio antenna for AM and FM radio reception is connected to the radio with a coaxial cable.
Conditions for Running the DTC
• Ignition ON/Vehicle in Service Mode.
• Battery voltage must be between 9 - 16 V
Conditions for Setting the DTC
The radio detects a short to ground in the antenna signal circuit center conductor.
The radio detects an open in the antenna signal circuit center conductor.
The radio detects a short to battery in the antenna signal circuit center conductor.
Action Taken When the DTC Sets
Radio reception may be poor or not available.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clears after 50 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
Poor AM and FM radio reception is dependent on multiple influences, some of which may not be vehicle related.
Areas which have high RF traffic or block the signal path may cause a degradation in radio reception. Radio
reception may also be influenced by items within the vehicle, but are not part of the radio system. Such examples are
aftermarket electrical accessories or other items which may generate noise in the vehicle electrical system.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Inspect the antenna for proper mounting or physical damage.
• If damage is found
Repair or replace as necessary
2. Ignition ON/Vehicle in Service Mode, A11 Radio ON.
3. Verify station reception is normal when tuned to several known good AM and FM stations.
• If AM or FM reception is poor.
Refer to Circuit/System Testing
4. All OK.
Circuit/System Testing
1. Ignition OFF/Vehicle OFF, disconnect the radio antenna coax cable from the A11 Radio and from the T2RR
Antenna - Roof Rear.
2. Verify the antenna coax cable passes the coax cable component test. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the antenna coax cable
3. Connect the antenna coax cable to the T2RR Antenna - Roof Rear.
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield at the radio
end of the coax cable.
Replace the radio antenna base.
5. Test for less than 10 Q between the coax cable outer shield and ground at the radio end of the coax cable.
1. Clean the mounting surface of the radio antenna base.
2. Connect the antenna coax cable to the T2RR Antenna - Roof Rear.
3. Test for less than 10 Q between the coax cable outer shield and ground at the radio end of the coax
cable.
• If 10 Q or greater, replace the antenna base.
• If less than 10 Q, connect all harness connectors. Verify station reception is normal when tuned to
several known good AM and FM stations. If AM or FM reception concerns are still present,
replace the A11 Radio.
6. Test or replace the A11 Radio.
Component Testing
CAUTION: Refer to Test Probe Caution .
NOTE: Before testing the coax cable, check the cable exterior for being pinched, cut,
damaged, or having loose connections at the components, which can cause
reception issues.
To prevent false reading when testing the center coax terminals, use care not to
ground the test probe on the outer housing/shield.
1. Ignition OFF/Vehicle OFF, disconnect the coax cable at both components.
2. Test for less than 5 Q between coax cable center terminal end to end.
• If 5 fi or greater
Replace the coax cable
3. Test for less than 5 Q between the coax cable outer shield end to end.
• If 5 fi or greater
Replace the coax cable
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
Replace the coax cable
5. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• Refer to Control Module References for radio replacement, programming, and setup.
DTC B125C: SATELLITE ANTENNA CIRCUIT
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Satellite Antenna Circuit Short to Battery
Satellite Antenna Circuit Short to Ground
Satellite Antenna Circuit Open
Circuit/System Description
The digital radio receiver, located inside the radio, receives digital radio information from the digital radio antenna
located on the outside of the vehicle. The digital radio receiver is connected to the digital radio antenna via a shielded
coax cable. The digital radio antenna contains an amplifier which is powered by the radio through the coax cable.
Conditions for Running the DTC
This DTC is run every 300 milliseconds.
Conditions for Setting the DTC
The radio detects a circuit fault in the digital radio antenna.
Action Taken When the DTC Sets
The radio displays No XM Signal or Check Antenna.
Conditions for Clearing the DTC
• A current DTC clears when the condition for setting the DTC is no longer present.
• A history DTC clears after 100 malfunction-free ignition cycles.
Diagnostic Aids
The digital radio antenna requires a clear line of sight to the sky to operate properly. Reception may be limited,
intermittent, or unavailable inside structures.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Special Tools
EL-48028 Digital Radio Test Antenna
Circuit/System Verification
1. With the vehicle outside in an area with an unobstructed view of the southern sky, tune to XM.
2. Verify DTC B125C is not set as current and the No XM Signal message is not displayed on the radio.
• If DTC B125C is set as current or the No XM Signal message is displayed.
Refer to Circuit/System Testing.
3. All OK.
Circuit/System Testing
1. Ignition OFF/Vehicle OFF, disconnect the digital radio antenna coax cable from the A11 Radio. Connect the
EL-48028 Digital Radio Test Antenna to the radio and place on the roof of the vehicle.
2. Ignition ON/Vehicle in Service Mode, radio tuned to XM channel 1.
3. Verify DTC B125C is not set as current and XM reception is improved.
• If DTC B125C is set as current or XM reception is not improved
Replace the A11 Radio.
4. Ignition OFF/Vehicle OFF, disconnect the digital radio antenna coax cable from the T2RR Antenna - Roof
Rear.
5. Verify the digital radio antenna coax cable passes the coax cable component test. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the antenna coax cable
• If the coax cable passes the test
6. Test or replace the T2RR Antenna - Roof Rear.
Component Testing
CAUTION: Refer to Test Probe Caution .
NOTE: Before testing the coax cable, check the cable exterior for being pinched, cut,
damaged, or having loose connections at the components, which can cause
reception issues.
To prevent false reading when testing the center coax terminals, use care not to
ground the test probe on the outer housing/shield.
Coax Cable Test
1. Ignition OFF/Vehicle OFF, disconnect the coax cable at both components.
2. Test for less than 5 Q between coax cable center terminal end to end.
• If 5 fi or greater
Replace the coax cable
• If less than 5 fi
3. Test for less than 5 Q between the coax cable outer shield end to end.
• If 5 fi or greater
Replace the coax cable
• If less than 5 fi
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
• If less than infinite resistance
Replace the coax cable
• If infinite resistance
5. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to High Frequency Antenna Replacement
• Refer to Control Module References for radio replacement, programming, and setup.
DTC B1271: THEFT PROTECTION ACTIVE
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Theft Protection Active
Circuit/System Description
When the radio is initially installed in the vehicle, the radio receives VIN information via serial data. The radio stores
a portion of the VIN and compares this sequence to the VIN information received each time the radio powers on. The
VIN in the radio is a single one-time learn.
The radio theft deterrent system is intended to disable or limit radio functionality if incorrect vehicle information is
received by the radio. The radio disables functionality if the VIN information received by the radio does not match
the VIN information that has been learned by the radio. This DTC is generated by the module when the Theft
Protection is activated.
Conditions for Running the DTC
This DTC test runs when the radio changes from OFF to ON.
Conditions for Setting the DTC
The radio has learned a correct VIN sequence and the VIN information received via serial data does NOT match the
learned VIN sequence.
Action Taken When the DTC Sets
The radio may be disabled or have limited functionality. The radio display will indicate that theft protection is active.
Conditions for Clearing the DTC
The radio receives the correct VIN information via serial data.
Diagnostic Aids
A possible cause of incorrect VIN info could be the radio was originally installed in another vehicle.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Vehicle in Service Mode, radio ON.
2. Verify DTC B1271 is not set.
Replace the A11 Radio.
3. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for radio replacement, programming, and setup.
DTC B127E: FRONT VIDEO DISPLAY OUTPUT SIGNAL
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Front Video Display Output Signal
Circuit/System Description
The infotainment display and controls are a separate component from the radio, combined into an assembly. The
assembly is supplied battery voltage and ground from the vehicle harness. The human machine interface control
module communicates digital video data for on-screen display through a dedicated cable containing the LVDS data
circuits.
Control information, touch communications and dimming level for the display are communicated via a LIN serial
data circuit to the human machine interface control module.
If the human machine interface control module detects the display is not responding to the output on the LVDS
circuits, the human machine interface control module sets the DTC.
Conditions for Running the DTC
• Ignition is ON or in the ACC position
• The system voltage is 9-16 V
• The infotainment system is ON
• The test is continuously when the infotainment system is operating
Conditions for Setting the DTC
The human machine interface control module detects the display is not responding to the output on the LVDS
circuits.
Action Taken When the DTC Sets
• The human machine interface control module sets this DTC
• No images are shown on the Info Display Module
Conditions for Clearing the DTC
• The human machine interface control module detects a properly synced digital video signal.
• A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
• EL-50334-2 Type A female to Mini B male USB Cable
• EL-50334-14 Infotainment Test Cable
Circuit/System Testing
1. Vehicle OFF/Ignition OFF.
2. Verify the LVDS interface cable is properly connected at the P17 Info Display Module and the K74 Human
Machine Interface Control Module connections and there is no damage to the cable or connections.
3. Ignition ON/Vehicle in Service Mode, infotainment system ON.
4. Verify the P17 Info Display Module does not display an image.
• If the P17 Info Display Module displays an image.
All OK.
5. Vehicle OFF/Ignition OFF.
6. Disconnect the LVDS interface cable from the P17 Info Display Module.
7. Connect the EL-50334-2 Type A female to Mini B male USB Cable to the P17 Info Display Module. Connect
the EL-50334-14 Infotainment Test Cable to the adapter.
8. Disconnect the LVDS interface cable from the K74 Human Machine Interface Control Module. Connect the
EL-50334-14 Infotainment Test cable to the K74 Human Machine Interface Module.
9. Ignition ON/Vehicle in Service Mode, infotainment system ON.
10. Verify the P17 Info Display Module displays an image.
• If the P17 Info Display Module does not display an image
1. Replace the P17 Info Display Module. Connect all harness connectors.
2. Ignition ON/Vehicle in Service Mode, infotainment system ON.
3. Verify the P17 Info Display Module displays an image.
• If the P17 Info Display Module still does not display an image, replace the K74 Human Machine
Interface Control Module.
• If the P17 Info Display Module displays an image.
4. All OK.
• If the P17 Info Display Module displays an image.
11. Replace the vehicle LVDS interface cable from the P17 Info Display Module to the K74 Human Machine
Interface Module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for human machine interface control module replacement,
programming, and setup.
DTC B12A8: OPTICAL MEDIA DRIVE THEFT LOCKED
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Optical Media Drive Theft Locked
Circuit/System Description
When the Media Disc Player is initially installed in the vehicle, it receives VIN information via serial data. The
Media Disc Player stores a portion of the VIN and compares this sequence to the VIN information received each
time the Media Disc Player powers on. The VIN in the Media Disc Player is a single one-time learn.
The Media Disc Player theft deterrent system is intended to disable or limit Media Disc Player functionality if
incorrect vehicle information is received by the Media Disc Player. The Media Disc Player disables functionality if
the VIN information received by the Media Disc Player does not match the VIN information that has been learned by
the Media Disc Player. This DTC is generated by the module when the Theft Protection is activated.
Conditions for Running the DTC
This test runs once per second while the Media Disc Player is being accessed.
Conditions for Setting the DTC
The Media Disc Player has learned a correct VIN sequence and the VIN information received via serial data does
NOT match the learned VIN sequence.
Action Taken When the DTC Sets
The Media Disc Player may be disabled or have limited functionality.
Conditions for Clearing the DTC
The Media Disc Player receives the correct VIN information via serial data.
Diagnostic Aids
A possible cause of incorrect VIN information could be the Media Disc Player was originally installed in another
vehicle.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Vehicle in Service Mode.
2. Verify DTC B12A8 is not set.
Replace the A33 Media Disc Player.
3. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for media disc player replacement, programming, and setup.
DTC B1446 OR B1447: BACKUP POWER SOURCE
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Replace Backup Power Source Below Minimum Threshold
Backup Power Source Open Circuit
For symptom byte information refer to Symptom Byte List
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Diagnostic Fault Information | |||||||||||||||
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Circuit/System Description |
The backup power source provides voltage to the telematics communication interface control module, to be able to
successfully place a call in the event of a main battery disconnect during a collision event.
Conditions for Running the DTC
• Ignition On/Vehicle in Service Mode.
• System voltage is between 9.5 and 15.5 V.
• DTC B1447 is not set.
• Ignition On/Vehicle in Service Mode.
• System voltage is between 9.5 and 15.5 V.
• The above conditions are present for greater than 10 s.
Conditions for Setting the DTC
The telematics communication interface control module detects that the backup power source voltage has dropped
below the minimum threshold value.
The telematics communication interface control module detects no voltage from the backup power source.
Action Taken When the DTC Sets
The OnStarA® status LED turns red.
• The OnStarA® status LED turns red.
• The telematics communication interface control module will be unable to place a call in the event of a main
battery disconnect during a collision event.
Conditions for Clearing the DTC
• A current DTC B1446 will clear when the telematics communication interface control module detects the
voltage of the backup power source is above the minimum threshold value.
• A current DTC B1447 will clear when the telematics communication interface control module detects voltage
from the backup power source.
• A history DTC clears after 50 malfunction-free ignition cycles.
Diagnostic Aids
• Shorting the backup power source positive voltage circuit to the backup power source ground circuit or chassis
ground will activate the internal circuit protection of the backup power source, rendering the backup power
source inoperative.
• DTC B1447 may set if the K73 Telematics Communication Interface Control Module has been incorrectly
disconnected or serviced. When disconnecting the K73 Telematics Communication Interface Control Module,
disconnect the harness connector X1 at the K73 Telematics Communication Interface Control Module prior to
disconnecting any other harness connectors. This will ensure the backup power source is preserved when
voltage is removed from the K73 Telematics Communication Interface Control Module.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Testing for Intermittent Conditions and Poor Connections
Circuit Testing
Wiring Repairs
Connector Repairs
Circuit/System Testing
1. Ignition OFF/Vehicle OFF and all vehicle systems OFF, disconnect the X1 harness connector at the K73
Telematics Communication Interface Control Module. It may take up to 2 minutes for all vehicle systems to
power down.
2. Test for greater than 12.3 V between the B+ circuit terminal 14 and the low reference circuit terminal 13.
1. Disconnect the C3 Telematics Communication Interface Control Module Battery.
2. Test for infinite resistance between the circuits listed below and ground.
• B+ circuit terminal 14
• Low reference circuit terminal 13.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance.
3. Test for less than 2 Q in the circuits end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the C3 Telematics Communication Interface Control Module Battery.
• If greater than 12.3 V
3. Replace the K73 Telematics Communication Interface Control Module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for telematics communication interface control module replacement,
programming and setup.
DTC B2455: CELLULAR PHONE MICROPHONE CIRCUIT
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Cellular Phone Microphone Circuit Short to Ground
DTC B2455 04
Cellular Phone Microphone Circuit Open
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Diagnostic Fault Information | |||||||||||||||
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Circuit/System Description |
The telematics communication interface control module provides the cellular phone microphone with a supplied
voltage on the cellular phone microphone high signal circuit. When the microphone is in use, voice data from the
user is sent back to the telematics communication interface control module on the microphone low signal circuit.
Conditions for Running the DTC
• The Vehicle must be ON or in Service Mode.
• The system voltage is at least 9.5 V and no more than 15.5 V.
• All the above conditions are present for greater than 10 s.
Conditions for Setting the DTC
The telematics communication interface control module detects a short to ground in the cellular phone microphone
signal circuit for 10 s or greater.
The following conditions will set this DTC:
• The telematics communication interface control module detects an open/high resistance in the cellular phone
microphone signal circuit for 10 s or greater.
• The telematics communication interface control module detects an open/high resistance in the low signal
circuit for 10 s or greater.
Action Taken When the DTC Sets
• The OnStarA® status LED turns red.
• The telematics communication interface control module will not receive a signal from the cellular phone
microphone.
• Calls can be placed but the caller cannot be heard.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF/Vehicle OFF, disconnect the harness connector at the B24 cellular phone microphone, Ignition
ON/Vehicle in Service Mode.
2. Test for 8.0-10.5 V between the signal circuit terminal B and ground.
1. Ignition OFF/Vehicle OFF, disconnect the X2 harness connector at the K73 telematics communication
interface control module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the vehicle K73 Telematics Communication Interface Control Module.
• If greater than 10.5 V
1. Ignition OFF/Vehicle OFF, disconnect the X2 harness connector at the K73 telematics communication
interface control module, Ignition ON/Vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K73 Telematics Communication Interface Control Module.
3. Test for less than 1 V between the signal circuit terminal A and ground.
• If greater than 1 V
1. Ignition OFF/Vehicle OFF, disconnect the X2 harness connector at the K73 telematics communication
interface control module, Ignition ON/Vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage in the circuit.
• If less than 1 V, repair the K73 Telematics Communication Interface Control Module.
4. Test for greater than 8 V between the signal circuit terminal B and the signal circuit terminal A.
1. Ignition OFF/Vehicle OFF, disconnect the connector X2 at the K73 telematics communication interface
control module.
2. Test for infinite resistance between the low signal circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the vehicle K73 Telematics Communication Interface Control Module.
• If greater than 8 V
5. Test or replace the B24 Cellular Phone Microphone.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for telematics communication interface control module replacement,
programming and setup.
DTC B2462: GLOBAL POSITIONING SYSTEM
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Global Positioning System Short to Ground
Global Positioning System Open
Circuit/System Description
The navigation antenna is connected to the Telematics Communication Interface Control Module. The module
supplies 5 V to the antenna to power the internal amplifier through the center conductor of the antenna coax cable.
When the vehicle is equipped with the optional navigation system, a Navigation Antenna Signal Splitter is installed
to distribute the navigation signal to both the Telematics Communication Interface Control Module and the Human
Machine Interface Control Module. The Human Machine Interface Control Module supplies 5 V through the coax
cable to power the Navigation Antenna Signal Splitter.
Conditions for Running the DTC
• Radio On.
• System voltage is greater than 9 V and less than 16 V
• The navigation system/telematics communication interface control module tests the GPS antenna every 10 s.
Conditions for Setting the DTC
The Telematics Communication Interface Control Module or Human Machine Interface Control Module detects a
short to ground on the GPS antenna signal circuit.
The Telematics Communication Interface Control Module or Human Machine Interface Control Module detects a
open/high resistance on the GPS antenna signal circuit.
Action Taken When the DTC Sets
• The Telematics Communication Interface Control Module or Human Machine Interface Control Module uses
the last reported position and the vehicle speed signal to calculate the vehicle position.
• Route guidance may be inaccurate.
• Turn by turn navigation may be inaccurate or inoperative.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear once 50 consecutive malfunction - free ignition cycles have occurred.
Diagnostic Aids
• The scan tool Telematics Communication Interface Control Module GPS signal parameter will display a Yes or
No dependent upon whether or not the module sees an increment of the seconds transmitted by GPS signals to
the Telematics Communication Interface Control Module. Upon entering this screen, the GPS signal title will
initially display Yes, regardless of the presence of time increment, for at least 2 seconds, while the algorithm in
the scan tool determines the status of the clock. If increment is found, Yes is continually displayed. If the clock
remains static, No is displayed. The scan tool looks for increment every second, regardless of current display.
• Inaccurate or aged GPS position concerns which are no longer present may have been due to the temporary
loss of GPS signal reception by the vehicle. Conditions such as tunnels or parking structures will restrict the
cellular phone and navigation antenna from a clear view of the satellites in the sky and may have caused this
temporary data loss.
• The GPS requires a clear line of sight to the sky to operate properly. In most cases the GPS will not have
reception near tall buildings or inside structures.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-49903 OnStar Antenna Diagnostic Tool Kit
Circuit/System Verification
NOTE: The following verification requires the vehicle to be outside with an unobstructed
view of the southern sky. Allow 5 minutes after turning the ignition ON for the
vehicle to acquire the GPS satellites signal.
1. Ignition ON/vehicle in Service Mode.
2. Verify that DTC B2462 is not set in the Telematics Communication Interface Control Module.
• If DTC B2462 is set in the Telematics Communication Interface Control Module and the vehicle is
not equipped with a navigation system
Refer to Circuit/System Testing Without Navigation System.
Refer to Circuit/System Testing With Navigation System.
3. Verify an OnStar advisor can locate the vehicle after performing a blue button press.
• If the advisor can not locate the vehicle and the vehicle is not equipped with a navigation system
Refer to Circuit/System Testing Without Navigation System
Refer to Circuit/System Testing With Navigation System.
4. Verify DTC B2462 is not set in the Human Machine Interface Control Module.
Refer to Circuit/System Testing With Navigation System - Step 9.
5. Verify that the NO GPS symbol/message is not displayed on the radio display.
• If the NO GPS symbol/message is displayed
Refer to Circuit/System Testing With Navigation System - Step 9.
6. All OK.
Circuit/System Testing
without Navigation System
NOTE: You must perform the Circuit/System Verification before proceeding with
Circuit/System Testing.
1. Ignition OFF/vehicle OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics
Communication Interface Control Module.
2. Attach both leads of the EL-49903-1 OnStar test antenna to the EL-49903-5 combiner. Using the EL-49903-6
coax cable attach the grey connector to the combiner and the brown connector to the K73 Telematics
Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON.
3. Verify DTC B2462 is not set or that the OnStar advisor can locate the vehicle.
Replace the K73 Telematics Communication Interface Control Module.
4. Test the coax cable between the K73 Telematics Communication Interface Control Module and the T2RR
Antenna - Roof Rear. Refer to component testing.
• If the coax cable does not pass the test
Replace the coax cable.
5. Test or replace the T2RR Antenna - Roof Rear.
with Navigation System
NOTE: You must perform the Circuit/System Verification before proceeding with
Circuit/System Testing.
1. Ignition OFF/vehicle OFF, disconnect the T2RR Antenna - Roof Rear coax cable at the T15 Navigation
Antenna Signal Splitter.
2. Attach both leads of the EL-49903-1 OnStar test antenna to the EL-49903-5 combiner. Using the EL-49903-7
coax cable attach one grey connector to the combiner and the other grey connector to the T15 Navigation
Antenna Signal Splitter. Place the test antenna on the roof of the vehicle, ignition ON.
3. Verify DTC B2462 is not set or that the OnStar advisor can locate the vehicle.
1. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the T2RR Antenna - Roof
Rear. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the coax cable.
• If the coax cable passes the test
2. Replace the T2RR Antenna - Roof Rear.
4. Ignition OFF/vehicle OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics
Communication Interface Control Module.
5. Attach both leads of the EL-49903-1 OnStar test antenna to the EL-49903-5 combiner. Using the EL-49903-6
coax cable attach the grey connector to the combiner and the brown connector to the K73 Telematics
Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON.
6. Verify DTC B2462 is not set or that the OnStar advisor can locate the vehicle.
Replace the K73 Telematics Communication Interface Control Module.
7. Ignition OFF/vehicle OFF.
8. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the K73 Telematics
Communication Interface Control Module. Refer to Component Testing.
• If the coax cable does not pass the test.
Replace the coax cable.
9. Ignition OFF/vehicle OFF, disconnect the blue GPS coax cable connector at the K74 Human Machine
Interface Control Module.
10. Attach the EL-49903-1 OnStar test antenna blue connector to the K74 Human Machine Interface Control
Module and place the test antenna on the roof of the vehicle.
11. Ignition ON/vehicle in Service Mode.
12. Verify DTC B2462 is not set or that the NO GPS symbol/message is not displayed on the radio.
• If DTC B2462 is set or the NO GPS symbol/message is displayed
Replace the K74 Human Machine Interface Control Module
13. Ignition OFF/vehicle OFF.
14. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the K74 Human Machine
Interface Control Module. Refer to Component Testing.
• If the coax cable does not pass the test.
Replace the coax cable.
15. Test or replace the T15 Navigation Antenna Signal Splitter.
Component Testing
CAUTION: Refer to Test Probe Caution .
|
NOTE: |
|
1. Ignition OFF/vehicle OFF, disconnect the coax cable at both components.
2. Test for less than 5 Q between the coax cable center terminal end to end.
• If 5 fi or greater
Replace the coax cable.
• If less than 5 fi
3. Test for greater than 5 Q between the coax cable outer shield end to end.
Replace the coax cable.
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
Replace the coax cable.
5. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for Human Machine Interface control module or Telematics
Communication Interface Control Module replacement, programming, and setup.
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Cellular Phone Antenna Circuit Malfunction Short to Ground
Cellular Phone Antenna Circuit Malfunction Open Circuit
Circuit/System Description
The primary cellular phone antenna element is connected to the telematics communication interface control module
(violet connector) via a shielded coaxial cable. Cellular communication takes place on both the primary cellular
antenna signal circuit and the GPS/secondary cellular antenna signal circuit. This diagnostic only applies to the
primary cellular antenna signal circuit. Internal to the antenna on the cellular antenna signal circuit resistance is used
to apply a load, which the telematics communication interface control module uses to detect the presence of the
antenna.
Conditions for Running the DTC
• Ignition in the RUN or ACC position.
• System voltage is between 9.5 V and 15.5 V
• The above conditions are present for greater than 1 s.
Conditions for Setting the DTC
The telematics communication interface control module detects a short to ground on the primary cellular antenna
signal circuit.
• The telematics communication interface control module detects an open or high resistance on the primary
cellular antenna signal circuit.
• The above conditions are present for greater than 1 s.
Action Taken When the DTC Sets
The OnStarA® status LED turns red.
Conditions for Clearing the DTC
• The telematics communication interface control module detects the presence of a cellular antenna.
• A history DTC clears after 50 malfunction-free ignition cycles.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-49903-1 Test Antenna Navn-Cell Comn
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Circuit/System Testing | ||
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1. Ignition OFF/Vehicle OFF and all vehicle systems OFF, disconnect the violet primary cellular coax cable
connector at the K73 Telematics Communication Interface Control Module. It may take up to 2 min for all
vehicle systems to power down.
2. Using the EL-49903-1 Test Antenna Navn-Cell Comn connect the violet coax cable to the K73 Telematics
Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition
ON/vehicle in Service Mode.
3. Verify the DTC does not set or a call can be completed to the OnStar Call Center while operating the vehicle
within the conditions for running the DTC.
• If the DTC sets or a call can not be completed to the OnStar Call Center
Replace the K73 Telematics Communications Interface Control Module.
4. Ignition OFF/Vehicle OFF.
5. Disconnect the EL-49903-1 Test Antenna Navn-Cell Comn from the K73 Telematics Communication
Interface Control Module
6. Test the coax cable. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the coax cable.
7. Test or replace the T2RR Antenna - Roof Rear.
Component Testing
CAUTION: Refer to Test Probe Caution
|
NOTE: |
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1. Test for less than 5 Q between the coax cable center terminal end to end.
• If 5 fi or greater
Replace the coax cable.
2. Test for greater than 5 Q between the coax cable outer shield end to end.
Replace the coax cable.
3. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
Replace the coax cable.
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair procedure.
• Refer to Control Module References for telematics communication interface control module replacement,
setup, and programming
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Cellular Phone Select Service Switch Open
Cellular Phone Select Service Switch Protection Time-out
Cellular Phone Select Service Switch Range/Performance
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Diagnostic Fault Information | ||||||||||
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Circuit/System Description |
The OnStarA® button assembly consists of 3 buttons: Call/Answer, OnStarA® Call Center, and OnStarA®
Emergency. The telematics communication interface control module supplies the OnStarA® button assembly with 10
V via the 10 V reference circuit. Each of the buttons, when pressed, completes the circuit across a resistor allowing a
specific voltage to be returned to the telematics communication interface control module over the keypad signal
circuit. Depending upon the voltage range returned, the telematics communication interface control module is able to
identify which button has been pressed.
Conditions for Running the DTC
• Vehicle in Service Mode/Ignition ON.
• Battery voltage must be between 9 - 16 V
Conditions for Setting the DTC
The telematics communication interface control module detects an open/high resistance on the keypad supply
voltage circuit.
The telematics communication interface control module detects a valid signal on the keypad signal circuit for longer
than 15 s. If one of the OnStarA® buttons is held or stuck for 15 s or greater, the telematics communication interface
control module will set this DTC.
Action Taken When the DTC Sets
• The OnStarA® status LED turns red.
• No calls can be placed.
• The telematics communication interface control module will ignore all inputs from the OnStarA® button
assembly.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
After any repair is made to the 10 V reference circuit or button signal circuit the fuse to the telematics
communication interface control module must be removed for 30 s to reset the control module. Failure to do so could
result in incorrect diagnosis.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
NOTE:
• 10 V reference circuit measurement may vary with vehicle battery voltage.
• Test for voltage range with vehicle battery measuring at a minimum of 11.5 V
1. Vehicle OFF/Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S48B
Multifunction Switch - Overhead Console. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Q between the ground circuit terminal 5 and ground.
• If 10 fi or greater
1. Vehicle OFF/Ignition OFF.
2. Test for less than 2 Q in the ground circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, repair the open/high resistance in the ground connection.
3. Vehicle in Service Mode/Ignition ON.
4. Test for 8.0 - 10.5 V between the 10 V reference circuit terminal 16 and ground.
1. Vehicle OFF/Ignition OFF, disconnect the harness connector at the K73 Telematics Communication
Interface Control Module.
2. Test for infinite resistance between the 10 V reference circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the 10 V reference circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K73 Telematics Communication Interface Control Module.
• If greater than 10.5 V
1. Vehicle OFF/Ignition OFF, disconnect the harness connector at the K73 Telematics Communication
Interface Control Module, vehicle in Service Mode/Ignition ON.
2. Test for less than 1 V between the 10 V reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K73 Telematics Communication Interface Control Module.
5. Vehicle OFF/Ignition OFF.
6. Test for 500 - 900 Q between the signal circuit terminal 17 and ground.
1. Disconnect the X1 harness connector at the K73 Telematics Communication Interface Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K73 Telematics Communication Interface Control Module.
• If greater than 900 fi
1. Disconnect the X1 harness connector at the K73 Telematics Communication Interface Control Module,
vehicle in Service Mode/Ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Vehicle OFF.
4. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K73 Telematics Communication Interface Control Module.
7. Test or replace the S48B Multifunction Switch - Overhead Console.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for telematics communication interface control module replacement,
programming and setup.
SYMPTOMS - CELLULAR COMMUNICATION
NOTE: The following steps must be completed before using the symptom table.
1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of
the following are true:
• There are no DTCs set.
• The control modules can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to OnStar
Description and Operation.
Visual/Physical Inspection
• Inspect for aftermarket devices which could affect the operation of the Radio/Audio System. Refer to
Checking Aftermarket Accessories .
• Inspect for easily accessible or visible system components for obvious damage or conditions which could
cause the symptom.
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for
Intermittent Conditions and Poor Connections .
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
Bluetooth Malfunction
No Global Positioning System (GPS) Reception
OnStar Microphone Malfunction
OnStar Audio Malfunction
OnStar Button LED Malfunction
OnStar Call Center Remote Function Requests Malfunction
OnStar Button Malfunction
Unable to Contact OnStar Call Center
OnStar Voice Recognition Malfunction
OnStar Steering Wheel Control Functions Malfunction
IMPORTANT: The following steps must be completed before using the symptom table.
1. Perform the Diagnostic System Check - Vehicle before using the Symptom Tables in order to verify that all of
the following are true:
• There are no DTCs set.
• The control modules can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to Radio/Audio
System Description and Operation.
Visual/Physical Inspection
• Inspect for aftermarket devices which could affect the operation of the Radio/Audio System. Refer to
Checking Aftermarket Accessories .
• Inspect for easily accessible or visible system components for obvious damage or conditions which could
cause the symptom.
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for
Intermittent Conditions and Poor Connections .
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
Application Malfunction
Auxiliary Audio Input Malfunction
Bluetooth Malfunction
Digital Radio Poor or No Reception
Navigation System - Voice Recognition Malfunction
No Global Positioning System (GPS) Reception
Radio Poor Reception
Speaker Malfunction
APPLICATION MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
Circuit/System Description
The term application refers to any piece of software that works on a system (hardware) that is being operated by it's
own software. Applications are typically small software programs which uses the hardware to perform a specific
task, as opposed to operating the entire system.
Diagnostic Aids
• For an application to be used, it must be installed on both the vehicle infotainment system and a compatible
mobile device.
• The application must work correctly on the device to work with the vehicle infotainment system.
• The user may be required to log-in to the application on the mobile device before using the application from
the vehicle controls.
• Applications use the mobile device and connection to a service provider to operate. Connection quality issues,
or service provider data transmission issues can give the appearance of a vehicle malfunction.
• The device must be connected to the system. this may be done wirelessly via BluetoothA®, or via the vehicle
USB port.
When a mobile device is connected via BluetoothA®, some or all of the device controls may be unavailable
from the radio controls. This varies dependant upon the device being used. Refer to the vehicle owners
manual, supplements, and the device manufacturers information for information on devices, control, and
operation.
Refer to the device manufacturers information for the preferred connection method.
• The device must be unlocked, and any additional applications should be closed.
• If the device has any sound enhancement features such as noise reduction or echo control, these features
should be turned off.
• A low battery condition in the mobile device may not allow the device to connect to the system, or can create
communication issues with the device. Verify the device battery state of charge and re-charge or replace as
needed.
• If a 'Please See Device' or similar type error message is displayed, this may indicate the device has lost it's
connection to the vehicle, or the device has lost it's external data connection.
• If a cable is used for connection, attempt to connect the device using a different cable; cables can deteriorate
over time or become damaged.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify the application is installed on the mobile device and is up to date.
• If the application is not installed or is not up to date.
Install or update the application on the device.
2. Verify the application operates correctly on the mobile device.
• If the application is not operating correctly on the mobile device.
Refer to the application website
3. Verify the radio calibrations are current.
Reprogram the radio and re-evaluate the concern.
4. Verify the application is installed on the radio and is up to date.
• If the application is not installed or is not up to date.
Install or update the application on the radio.
5. Vehicle in Service Mode, radio ON, connect the mobile device to the infotainment system. Refer to the owners
manual for information on the preferred connection method for the device.
• If the mobile device cannot connect to the vehicle infotainment system.
• If unable to connect via Bluetooth, refer to Bluetooth Malfunction.
• If unable to connect via USB, refer to Auxiliary Audio Input Malfunction.
• If the mobile device connects to the vehicle infotainment system.
6. Launch the application.
7. Verify the applications operates properly with the vehicle infotainment system.
• If the application does not function properly
Refer to diagnostic aids.
8. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Refer to Control Module References for radio replacement, setup, and programming
AUXILIARY AUDIO INPUT MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
USB 1 Circuit
For symptom byte information refer to Symptom Byte List .
Diagnostic Fault Information
| Circuit | Short to | Open/High | Short to | Signal |
| |||||||||||||||||||||||||
|
Circuit/System Description | |||||||||||||||||||||||||
The infotainment system has a USB port and a Auxiliary Audio Input Jack located in the center console. The
receptacle assembly receives fused battery voltage and ground from the harness to power the internal hub device as
well as providing additional amperage to power USB devices.
The internal hub device interfaces directly with the human machine interface control module via a standard USB
cable. A Mini type USB connector is used to connect the human machine interface control module and the USB
receptacle. Standard USB male to female connections are typically used for connecting USB cables together where
an in-line connection is required. An in-line cable connection is typically found between the console and I/P harness.
When a portable audio playback device is connected to the 3.5 mm (1/8 in.) auxiliary audio input jack an internal
switch opens the detection signal circuit within the hub. The HMI detects the device and AUX becomes available as
an audio source. Audio signals from the device are converted from analog to digital, these signals are then sent to the
HMI from the auxiliary input jack via USB.
The USB port allows connectivity to the infotainment system from portable media players or a USB storage device
(memory stick/flash drive). When a device is connected to the USB port, the system detects the device and switches
to USB as the audio source. Once connected, the device can be controlled from the radio controls.
Not all portable media player devices or file types are compatible. Refer to the owner's manual for information on
USB devices, control, and operation.
Conditions for Running the DTC
• Ignition On/Vehicle in Service Mode.
• The system voltage is 9-16 V
• The infotainment system is ON
• The test is run once per second when the infotainment system is operating
Conditions for Setting the DTC
The human machine interface control module detects an excessive current condition on the USB 5 V circuit.
The human machine interface control module does not detect the vehicle hub device.
B124B 11
The human machine interface control module detects an additional hub device attached to the vehicle USB port.
Action Taken When the DTC Sets
The USB port is inoperative while the DTC is current.
Conditions for Clearing the DTC
• The condition for setting the DTC is no longer present.
• A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
• This DTC may be set due to the connection of an incompatible or faulty USB device.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
• EL-50334-20 Multi-Media Interface Tester (MIT)
• EL-50334-50 USB Cable and Adapter Kit
• EL-50334-14 Infotainment Test Cable
Circuit/System Verification
1. Verify DTC B124B is not set. Since occurrences of this DTC can be caused by an incompatible or faulty USB
device, review with the customer the conditions under which their concern occurred.
Refer to Circuit/System Testing.
2. Ignition On/Vehicle in Service Mode. Infotainment system ON.
3. Connect the EL-50334-20 Multi-Media Interface Tester (MIT) to the X83 Auxiliary Audio Input USB port and
select the USB test mode.
4. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the infotainment
system while operating the system to play audio from the test tool.
Refer to Circuit/System Testing
5. Verify the infotainment system can be switched to AUX as the audio source with the EL-50334-20 Multi-
Media Interface Tester (MIT) connected to the auxiliary audio input jack.
• If the infotainment system can not be switched to AUX as the audio source
Refer to Circuit/System Testing
6. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the vehicle
infotainment system while operating the test tool to begin audio playback.
Refer to Circuit/System Testing
7. All OK
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the X83 Auxiliary Audio Input.
2. Test for less than 10 Q between the ground circuit terminal 4 and ground.
• If 10 fi or greater
1. Ignition OFF.
2. Test for less than 2 Q in the ground circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, repair the open/high resistance in the ground connection.
3. Verify that a test lamp illuminates between the B+ circuit terminal 6 and ground.
• If the test lamp does not illuminate
1. Ignition OFF, remove the test lamp.
2. Test for less than 2 Q in the B+ circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If the test lamp illuminates
4. Verify the USB cable is properly connected at all components and in-line connections, and there is no damage
to the cable or connections.
• If connection problems or cable damage is noted.
Perform the appropriate repair or replacement to correct any issues.
• If no connection problems or cable damage is noted.
5. Connect the X1 harness connector at the X83 Auxiliary Audio Input.
6. Disconnect the vehicle USB cable X3 harness connector at the K74 Human Machine Interface Control Module
and the X83 Auxiliary Audio Input Adapter.
7. Connect the EL-50334-14 Infotainment Test Cable and the EL-50334-2 Type-A Female to Mini-B Male Cable
together. Connect the assembled test cable to the K74 Human Machine Interface Control Module and the X83
Auxiliary Audio Input.
8. Ignition On/Vehicle in Service Mode. Infotainment system ON.
9. Connect the EL-50334-20 Multi-Media Interface Tester (MIT) to the X83 Auxiliary Audio Input USB port and
select the USB test mode.
10. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the infotainment
system while operating the system to play audio from the test tool.
• If audio is not heard from the test tool
1. Replace the X83 Auxiliary Audio Input Adapter. Connect all harness connectors.
2. Connect the EL-50334-20 Multi-Media Interface Tester (MIT) to the X83 Auxiliary Audio Input USB
port and select the USB test mode.
3. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the
infotainment system while operating the system to play audio from the test tool.
• If audio is not heard from the test tool, replace the K74 Human Machine Interface Control
Module.
• If audio is heard from the test tool
11. Connect the EL-50334-20 Multi-Media Interface Tester (MIT) to the X83 Auxiliary Audio Input AUX port
and select the AUX test mode.
12. Verify the audio from the EL-50334-20 Multi-Media Interface Tester (MIT) is heard through the infotainment
system while operating the system to play audio from the test tool.
• If audio is not heard from the test tool
1. Replace the X83 Auxiliary Audio Input Adapter. Connect all harness connectors.
• If audio is heard from the test tool.
13. Replace the vehicle USB cable between the K74 Human Machine Interface Control Module and the X83
Auxiliary Audio Input Adapter.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Audio Disc Player and USB Receptacle Replacement
• Refer to Control Module References for human machine interface control module replacement,
programming, and setup.
BLUETOOTH MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
Circuit/System Description
BluetoothA® wireless technology is a short-range communications technology intended to replace the cables
connecting portable and/or fixed devices while maintaining high levels of security. The operating range of the signal
is approximately 30 feet.
The available features and functions are determined by the type of device and the software within the devices being
used. For a feature or function to operate, it must be supported in both devices.
The BluetoothA® hardware is internal to the radio. The radio supports streaming of data (music, voice, information)
from cellular phones and other mobile devices that support those features. The radio may also be capable of
interfacing with cellular phones for hands-free features.
Refer to the vehicle owners manual, supplements, and the device manufacturers information for information on
devices, control, operation. and pairing instructions.
Diagnostic Aids
• Verify the mobile device is properly configured for the feature being used. Refer to the device manufacturers
information.
• Verify the function/feature that is being used is supported by the mobile device.
• The device must be paired to the radio to use the available BluetoothA® feature(s). The pairing process must
only be performed once for each device, unless that device's information is deleted.
• The system can store pairing information for multiple devices, but can only be actively connected to one at any
given time.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-50334-20 Multi-Media Interface Tester (MIT)
Circuit/System Verification
1. Verify no DTCs are present.
• If any DTCs are present
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
• If no DTCs are present
2. Verify the radio calibrations are current.
• If the radio calibrations are not current
Reprogram the radio and re-evaluate the concern.
• If no update calibrations are available
NOTE: The MIT tool can be used to test either cellular phone or streaming audio
functions. Refer to the tool instructions, and perform the appropriate test(s)
related to the customers concern in the following steps.
3. Vehicle in Service Mode, infotainment system ON.
4. Verify the infotainment system successfully pairs with the MIT tool.
• If the infotainment system does not successfully pair with the MIT tool.
Replace the A11 radio.
• If the infotainment system successfully pairs with the MIT tool.
5. Verify the infotainment system successfully completes the desired feature test using the MIT tool.
• If the feature test is not successful
Replace the A11 radio.
• If the feature test is successful
6. All OK. Refer to Diagnostic Aids.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for radio replacement, programming, and setup.
DIGITAL RADIO POOR OR NO RECEPTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Satellite Antenna Circuit Short to Battery
Satellite Antenna Circuit Short to Ground
Satellite Antenna Circuit Open
Circuit/System Description
The digital radio receiver, located inside the radio, receives digital radio information from the digital radio antenna
located on the outside of the vehicle. The digital radio receiver is connected to the digital radio antenna via a shielded
coax cable. The digital radio antenna contains an amplifier which is powered by the radio through the coax cable.
Conditions for Running the DTC
This DTC is run every 300 milliseconds.
Conditions for Setting the DTC
The radio detects a circuit fault in the digital radio antenna.
Action Taken When the DTC Sets
The radio displays No XM Signal or Check Antenna.
Conditions for Clearing the DTC
• A current DTC clears when the condition for setting the DTC is no longer present.
• A history DTC clears after 100 malfunction-free ignition cycles.
Diagnostic Aids
The digital radio antenna requires a clear line of sight to the sky to operate properly. Reception may be limited,
intermittent, or unavailable inside structures.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Special Tools
EL-48028 Digital Radio Test Antenna
Circuit/System Verification
1. With the vehicle outside in an area with an unobstructed view of the southern sky, tune to XM.
2. Verify DTC B125C is not set as current and the No XM Signal message is not displayed on the radio.
• If DTC B125C is set as current or the No XM Signal message is displayed.
Refer to Circuit/System Testing.
3. All OK.
Circuit/System Testing
1. Ignition OFF/Vehicle OFF, disconnect the digital radio antenna coax cable from the A11 Radio. Connect the
EL-48028 Digital Radio Test Antenna to the radio and place on the roof of the vehicle.
2. Ignition ON/Vehicle in Service Mode, radio tuned to XM channel 1.
3. Verify DTC B125C is not set as current and XM reception is improved.
• If DTC B125C is set as current or XM reception is not improved
Replace the A11 Radio.
4. Ignition OFF/Vehicle OFF, disconnect the digital radio antenna coax cable from the T2RR Antenna - Roof
Rear.
5. Verify the digital radio antenna coax cable passes the coax cable component test. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the antenna coax cable
6. Test or replace the T2RR Antenna - Roof Rear.
Component Testing
CAUTION: Refer to Test Probe Caution .
NOTE: Before testing the coax cable, check the cable exterior for being pinched, cut,
damaged, or having loose connections at the components, which can cause
reception issues.
To prevent false reading when testing the center coax terminals, use care not to
ground the test probe on the outer housing/shield.
1. Ignition OFF/Vehicle OFF, disconnect the coax cable at both components.
2. Test for less than 5 Q between coax cable center terminal end to end.
Replace the coax cable
3. Test for less than 5 Q between the coax cable outer shield end to end.
Replace the coax cable
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
Replace the coax cable
5. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for radio replacement, programming, and setup.
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
|
Diagnostic Fault Information | ||||||||||
|
| |||||||||||||||||||||||||
|
Circuit/System Description | |||||||||||||||||||||||||
The telematics communication interface control module provides the Cellular Phone Microphone with a supplied
voltage on the cellular phone microphone signal circuit. When the cellular phone microphone is in use, voice data
from the user is sent back to the telematics communication interface control module on the signal circuit.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE: It is necessary to have the vehicle in a quiet, open outside area where a cellular call
can be successfully placed and GPS data can be received from satellites.
1. Vehicle in Service Mode.
2. Verify that DTC B2455 is not set.
• If DTC B2455 is set
Refer to DTC B2455.
3. Verify that a successful OnStar voice command can be made.
• If your voice can not be heard clearly
Refer to Circuit/System Testing - Microphone Malfunction.
4. Verify that your voice is heard clearly by the OnStar Call Center after completing a blue button press.
• If your voice can not be heard clearly
Refer to Circuit/System Testing - Cellular Telephone Voice Malfunction.
5. All OK.
Circuit/System Testing
1. Vehicle OFF, disconnect the harness connector at the B24 Cellular Phone Microphone, vehicle in Service
Mode.
2. Test for 8.0-10.5 V between the signal circuit terminal B and ground.
1. Vehicle OFF, disconnect the X2 harness connector at the K73 Telematics Communication Interface
Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the vehicle K73 Telematics Communication Interface Control Module.
• If greater than 10.5 V
1. Vehicle OFF, disconnect the X2 harness connector at the K73 Telematics Communication Interface
Control Module, vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K73 Telematics Communication Interface Control Module.
3. Test for less than 1 V between the signal circuit terminal A and ground.
• If greater than 1 V
1. Vehicle OFF, disconnect the X2 harness connector at the K73 Telematics Communication Interface
Control Module, vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage in the circuit.
• If less than 1 V, repair the K73 Telematics Communication Interface Control Module.
4. Test for greater than 8 V between the signal circuit terminal B and the signal circuit terminal A.
1. Vehicle OFF, disconnect the X2 harness connector at the K73 Telematics Communication Interface
Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the vehicle K73 Telematics Communication Interface Control Module.
• If greater than 9 V
5. Test or replace the B24 Cellular Phone Microphone.
1. Vehicle OFF and vehicle systems OFF, disconnect the X2 harness connector at the K73 Telematics
Communication Interface Control Module and the X4 harness connector at the A11 Radio, vehicle in Service
Mode.
2. Test for less than 1 V between the signal circuits listed below and ground.
• K73 Telematics Communication Interface Control Module signal circuit Terminal 6
• K73 Telematics Communication Interface Control Module signal circuit Terminal 12
• If greater than 1 V
Repair the short to voltage in the circuit.
3. Vehicle OFF.
4. Test for infinite resistance between the signal circuits listed below and ground.
• K73 Telematics Communication Interface Control Module signal circuit Terminal 6
• K73 Telematics Communication Interface Control Module signal circuit Terminal 12
Repair the short to ground on the circuit.
5. Test for less than 2 Q in the signal circuits listed below end to end.
• K73 Telematics Communication Interface Control Module signal circuit Terminal 6
• K73 Telematics Communication Interface Control Module signal circuit Terminal 12
• If 2 fi or greater
Repair the open/high resistance in the circuit.
6. Replace the K73 Telematics Communication Interface Control Module.
7. Verify that your voice is heard clearly by the OnStar Call Center after completing a blue button press.
Replace the A11 Radio.
8. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair procedure.
• Refer to Control Module References for telematics communication interface control module replacement,
programming, and setup
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
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Diagnostic Fault Information | ||||||||||||||||||||
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Circuit/System Description | ||||||||||||||||||||
When voice recognition for the navigation equipped infotainment system is started, voice signals from the cellular
phone microphone are passed through the telematics communication interface control module to the radio via the
voice recognition audio circuits.
Diagnostic Aids
• Refer to the Navigation System Owners Manual for voice recognition use and commands.
• Navigation voice commands are not available until the OK button has been selected.
• If the radio is off, the only commands available will be Hands Free and Help.
• When the system recognizes the command the system will either perform the function or ask to confirm the
choice by clearly saying "yes" or "no".
• If experiencing difficulty with the system recognizing a command, confirm that the command is correct.
• Background noise such as a climate control fan positioned on high, open windows, or very loud outside noises,
can cause voice commands to be misunderstood.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify the OnStarA® voice recognition system is operating normally.
• If the OnStarA® voice recognition system is not operating normally.
Refer to OnStar Voice Recognition Malfunction.
• If the OnStarA® voice recognition system is operating normally.
2. Vehicle in Service Mode, radio ON.
NOTE: Refer to the Navigation System Owners Manual for voice recognition use and
commands.
3. Begin voice recognition for the radio and clearly speak one of the available commands.
4. Verify the infotainment system responds correctly to the command.
• If the infotainment system does not respond correctly to the command.
1. Clearly speak a different command.
2. Verify the infotainment system responds correctly to the command.
• If the infotainment system does not respond correctly to any commands, refer to Circuit/System
Testing.
• If the infotainment system responds correctly to the command.
3. Refer to the navigation system owners manual for hints on speaking commands.
• If the infotainment system responds correctly to the command.
5. All OK
Circuit/System Testing
1. Vehicle OFF, disconnect the X2 harness connector at the K73 Telematics Communication Interface Control
Module Control Module and the X4 harness connector at the A11 Radio.
2. Vehicle in Service Mode.
3. Test for less than 1 V between the signal circuits listed below and ground:
• voice recognition signal circuit A11 Radio X4 terminal 6
• voice recognition low reference circuit A11 Radio X4 terminal 16
• If 1 V greater
Repair the short to voltage on the circuit.
4. Vehicle OFF.
5. Test for infinite resistance between the circuits listed below and ground:
• voice recognition signal circuit A11 Radio X4 terminal 6
• voice recognition low reference circuit A11 Radio X4 terminal 16
Repair the short to ground on the circuit.
6. Test for less than 5 Q between the terminals listed below:
• A11 Radio X4 terminal 6 and the K73 Telematics Communication Interface Control Module Control
Module X2 terminal 6
• A11 Radio X4 terminal 16 and the K73 Telematics Communication Interface Control Module Control
Module X2 terminal 12
• If 5 fi greater
Repair the open/high resistance in the circuit.
7. Replace the A11 Radio. Connect all harness connectors.
NOTE: Refer to the Navigation System Owners Manual for voice recognition use and
commands.
8. Begin voice recognition for the radio and clearly speak one of the available commands.
9. Verify the infotainment system responds correctly to the command.
• If the infotainment system does not respond correctly to the command
1. Clearly speak a different command.
2. Verify the infotainment system responds correctly to the command.
• If the infotainment system does not respond correctly to any commands, replace the K73
Telematics Communication Interface Control Module.
10. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for radio or telematics communication interface control module replacement,
programming, and setup.
ONSTAR AUDIO MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
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Diagnostic Fault Information | ||||||||||||||||||||
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Circuit/System Description | ||||||||||||||||||||
When an OnStarA® keypress is made, a serial data message is sent to the audio system to mute all radio functions
and output OnStarA® originated audio. After the audio system is muted, the telematics communication interface
control module transmits signals to the audio system on the audio signal and audio common circuits.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
• Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Vehicle in Service Mode, radio ON.
2. Verify that audio is heard clearly through all speaker channels when tuning radio to a known good station.
• If audio is not heard clearly
Refer to Speaker Malfunction
• If audio is heard clearly
3. Verify that the Connecting to OnStarA® message is heard clearly through the audio system when the
OnStarA® blue button is pressed.
• If OnStar message is noisy or distorted
Refer to Circuit/System Testing
4. All OK.
Circuit/System Testing
1. Vehicle OFF, disconnect the X1 harness connector at the A11 Radio and the X2 harness connector at the K73
Telematics Communication Interface Control Module, vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit terminals listed below and ground:
• K73 Telematics Communication Interface Control Module signal circuit terminal 1 X2
• K73 Telematics Communication Interface Control Module signal circuit terminal 2 X2
• If 1 V or greater
Repair the short to voltage on the circuit.
3. Vehicle OFF.
4. Test for infinite resistance between the signal circuits listed below and ground:
• K73 Telematics Communication Interface Control Module signal circuit terminal 1 X2
• K73 Telematics Communication Interface Control Module signal circuit terminal 2 X2
Repair the short to ground on the circuit.
5. Test for less than 2 Q between the signal circuit terminals listed below:
• K73 Telematics Communication Interface Control Module signal circuit terminal 1 X2 and the A11
Radio signal circuit terminal 20 X1
• K73 Telematics Communication Interface Control Module signal circuit terminal 2 X2 and the A11
Radio signal circuit terminal 19 X1
• If 2 fi or greater
Repair the open/high resistance in the circuit.
6. Replace the K73 Telematics Communication Interface Control Module.
7. Verify that the Connecting to OnStarA® message is heard clearly through the audio system when the
OnStarA® blue button is pressed.
• If audio is not heard clearly
Replace the A11 Radio.
8. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for module replacement, programming, and setup.
NO GLOBAL POSITIONING SYSTEM (GPS) RECEPTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Global Positioning System Short to Ground
Global Positioning System Open
Circuit/System Description
The navigation antenna is connected to the Telematics Communication Interface Control Module. The module
supplies 5 V to the antenna to power the internal amplifier through the center conductor of the antenna coax cable.
When the vehicle is equipped with the optional navigation system, a Navigation Antenna Signal Splitter is installed
to distribute the navigation signal to both the Telematics Communication Interface Control Module and the Human
Machine Interface Control Module. The Human Machine Interface Control Module supplies 5 V through the coax
cable to power the Navigation Antenna Signal Splitter.
Conditions for Running the DTC
• Radio On.
• System voltage is greater than 9 V and less than 16 V
• The navigation system/telematics communication interface control module tests the GPS antenna every 10 s.
Conditions for Setting the DTC
The Telematics Communication Interface Control Module or Human Machine Interface Control Module detects a
short to ground on the GPS antenna signal circuit.
The Telematics Communication Interface Control Module or Human Machine Interface Control Module detects a
open/high resistance on the GPS antenna signal circuit.
Action Taken When the DTC Sets
• The Telematics Communication Interface Control Module or Human Machine Interface Control Module uses
the last reported position and the vehicle speed signal to calculate the vehicle position.
• Route guidance may be inaccurate.
• Turn by turn navigation may be inaccurate or inoperative.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear once 50 consecutive malfunction - free ignition cycles have occurred.
Diagnostic Aids
• The scan tool Telematics Communication Interface Control Module GPS signal parameter will display a Yes or
No dependent upon whether or not the module sees an increment of the seconds transmitted by GPS signals to
the Telematics Communication Interface Control Module. Upon entering this screen, the GPS signal title will
initially display Yes, regardless of the presence of time increment, for at least 2 seconds, while the algorithm in
the scan tool determines the status of the clock. If increment is found, Yes is continually displayed. If the clock
remains static, No is displayed. The scan tool looks for increment every second, regardless of current display.
• Inaccurate or aged GPS position concerns which are no longer present may have been due to the temporary
loss of GPS signal reception by the vehicle. Conditions such as tunnels or parking structures will restrict the
cellular phone and navigation antenna from a clear view of the satellites in the sky and may have caused this
temporary data loss.
• The GPS requires a clear line of sight to the sky to operate properly. In most cases the GPS will not have
reception near tall buildings or inside structures.
Reference Information
Schematic Reference
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
Description and Operation
OnStar Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-49903 OnStar Antenna Diagnostic Tool Kit
Circuit/System Verification
NOTE: The following verification requires the vehicle to be outside with an unobstructed
view of the southern sky. Allow 5 minutes after turning the ignition ON for the
vehicle to acquire the GPS satellites signal.
1. Ignition ON/vehicle in Service Mode.
2. Verify that DTC B2462 is not set in the Telematics Communication Interface Control Module.
• If DTC B2462 is set in the Telematics Communication Interface Control Module and the vehicle is
not equipped with a navigation system
Refer to Circuit/System Testing Without Navigation System.
• If DTC B2462 is set in the Telematics Communication Interface Control Module and the vehicle is
equipped with a navigation system
Refer to Circuit/System Testing With Navigation System.
• If DTC B2462 is not set in the Telematics Communication Interface Control Module
3. Verify an OnStar advisor can locate the vehicle after performing a blue button press.
• If the advisor can not locate the vehicle and the vehicle is not equipped with a navigation system
Refer to Circuit/System Testing Without Navigation System
• If the advisor can not locate the vehicle and the vehicle is equipped with a navigation system
Refer to Circuit/System Testing With Navigation System.
• If the advisor can locate the vehicle
4. Verify DTC B2462 is not set in the Human Machine Interface Control Module.
• If DTC B2462 is set in the Human Machine Interface Control Module
Refer to Circuit/System Testing With Navigation System - Step 9.
5. Verify that the NO GPS symbol/message is not displayed on the radio display.
• If the NO GPS symbol/message is displayed
Refer to Circuit/System Testing With Navigation System - Step 9.
6. All OK.
Circuit/System Testing
without Navigation System
NOTE: You must perform the Circuit/System Verification before proceeding with
Circuit/System Testing.
1. Ignition OFF/vehicle OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics
Communication Interface Control Module.
2. Attach both leads of the EL-49903-1 OnStar test antenna to the EL-49903-5 combiner. Using the EL-49903-6
coax cable attach the grey connector to the combiner and the brown connector to the K73 Telematics
Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON.
3. Verify DTC B2462 is not set or that the OnStar advisor can locate the vehicle.
Replace the K73 Telematics Communication Interface Control Module.
4. Test the coax cable between the K73 Telematics Communication Interface Control Module and the T2RR
Antenna - Roof Rear. Refer to component testing.
• If the coax cable does not pass the test
Replace the coax cable.
5. Test or replace the T2RR Antenna - Roof Rear.
with Navigation System
NOTE: You must perform the Circuit/System Verification before proceeding with
Circuit/System Testing.
1. Ignition OFF/vehicle OFF, disconnect the T2RR Antenna - Roof Rear coax cable at the T15 Navigation
Antenna Signal Splitter.
2. Attach both leads of the EL-49903-1 OnStar test antenna to the EL-49903-5 combiner. Using the EL-49903-7
coax cable attach one grey connector to the combiner and the other grey connector to the T15 Navigation
Antenna Signal Splitter. Place the test antenna on the roof of the vehicle, ignition ON.
3. Verify DTC B2462 is not set or that the OnStar advisor can locate the vehicle.
1. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the T2RR Antenna - Roof
Rear. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the coax cable.
• If the coax cable passes the test
2. Replace the T2RR Antenna - Roof Rear.
4. Ignition OFF/vehicle OFF, disconnect the GPS and cellular coax cable connector at the K73 Telematics
Communication Interface Control Module.
5. Attach both leads of the EL-49903-1 OnStar test antenna to the EL-49903-5 combiner. Using the EL-49903-6
coax cable attach the grey connector to the combiner and the brown connector to the K73 Telematics
Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition ON.
6. Verify DTC B2462 is not set or that the OnStar advisor can locate the vehicle.
Replace the K73 Telematics Communication Interface Control Module.
7. Ignition OFF/vehicle OFF.
8. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the K73 Telematics
Communication Interface Control Module. Refer to Component Testing.
• If the coax cable does not pass the test.
Replace the coax cable.
9. Ignition OFF/vehicle OFF, disconnect the blue GPS coax cable connector at the K74 Human Machine
Interface Control Module.
10. Attach the EL-49903-1 OnStar test antenna blue connector to the K74 Human Machine Interface Control
Module and place the test antenna on the roof of the vehicle.
11. Ignition ON/vehicle in Service Mode.
12. Verify DTC B2462 is not set or that the NO GPS symbol/message is not displayed on the radio.
• If DTC B2462 is set or the NO GPS symbol/message is displayed
Replace the K74 Human Machine Interface Control Module
13. Ignition OFF/vehicle OFF.
14. Test the coax cable between the T15 Navigation Antenna Signal Splitter and the K74 Human Machine
Interface Control Module. Refer to Component Testing.
• If the coax cable does not pass the test.
Replace the coax cable.
• If the coax cable passes the test.
15. Test or replace the T15 Navigation Antenna Signal Splitter.
Component Testing
CAUTION: Refer to Test Probe Caution .
|
NOTE: |
|
Coax Cable Test
1. Ignition OFF/vehicle OFF, disconnect the coax cable at both components.
2. Test for less than 5 Q between the coax cable center terminal end to end.
• If 5 fi or greater
Replace the coax cable.
• If less than 5 fi
3. Test for greater than 5 Q between the coax cable outer shield end to end.
• If 5 fi or greater
Replace the coax cable.
• If less than 5 fi
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
• If less than infinite resistance
Replace the coax cable.
• If infinite resistance
5. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to High Frequency Antenna Replacement
• Refer to Control Module References for Human Machine Interface control module or Telematics
Communication Interface Control Module replacement, programming, and setup.
ONSTAR BUTTON LED MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
|
Diagnostic Fault Information | ||||||||||||||||||||||||||||||
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Circuit Description | ||||||||||||||||||||||||||||||
The OnStarA® status LEDs are located with the OnStar buttons. The green LED is illuminated when the system is
ON and operating normally. When the green LED is green and flashing, it is an indication that a call is in progress.
When the red LED is illuminated, a system malfunction is present. In the event there is a system malfunction and the
OnStarA® system is still able to make a call, the LED will flash red during the call. The OnStarA® LEDs are
controlled by the telematics communication interface control module via the keypad green LED signal circuit and the
keypad red LED signal circuit.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE:
If the green LED is off with the ignition ON and the LED does not function
when commanded with the scan tool, contact the OnStar Center to confirm the
vehicle has a current subscription.
1. Vehicle in Service Mode/Ignition ON.
2. Verify no DTCs are set.
• If any DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle
• If no DTCs are set
3. Verify that the green LED turns ON and OFF when commanding the Green Indicator ON and OFF with a scan
tool.
• If the green LED does not turn ON and OFF
Refer to Circuit/System Testing - Green LED Test
4. Verify that the red LED turns ON and OFF when commanding the Red Indicator ON and OFF with a scan tool.
Refer to Circuit/System Testing - Red LED Test
5. All OK.
Circuit/System Testing
1. Vehicle OFF/Ignition OFF, and all vehicle systems OFF, disconnect the harness connector at the S48B
Multifunction Switch - Overhead Console. It may take up to 2 min for all vehicle systems to power down.
Doors closed, courtesy lamps OFF.
2. Test for less than 10 Q between the ground circuit terminal 5 and ground.
• If 10 fi or greater
1. Vehicle OFF/Ignition OFF.
2. Test for less than 2 Q in the ground circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, repair the open/high resistance in the ground connection.
3. Vehicle in Service Mode/Ignition ON.
4. Test for less than 1 V between the control circuit terminal 15 and ground while commanding the Green
Indicator OFF with a scan tool.
• If 1 V or greater
1. Vehicle OFF/Ignition OFF, disconnect the X1 harness connector at the K73 Telematics Communication
Interface Control Module, vehicle in Service Mode/Ignition ON.
2. Test for less than 1 V between the control circuit terminal 15 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K73 Telematics Communication Interface Control Module.
5. Test for greater than 8 V between the control circuit terminal 15 and ground while commanding the Green
Indicator ON with a scan tool.
1. Vehicle OFF/Ignition OFF, disconnect the X1 harness connector at the K73 Telematics Communication
Interface Control Module.
2. Test for infinite resistance between the control circuit terminal 15 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the control circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K73 Telematics Communication Interface Control Module.
• If greater than 8 V
6. Test or replace the S48B Multifunction Switch - Overhead Console.
1. Vehicle OFF/Ignition OFF, and all vehicle systems OFF, disconnect the harness connector at the S48B
Multifunction Switch - Overhead Console. It may take up to 2 min for all vehicle systems to power down.
Doors closed, courtesy lamps OFF.
2. Test for less than 10 Q between the ground circuit terminal 5 and ground.
• If 10 fi or greater
1. Vehicle OFF/Ignition OFF.
2. Test for less than 2 Q in the ground circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, repair the open/high resistance in the ground connection.
3. Vehicle in Service Mode/Ignition ON.
4. Test for less than 1 V between the control circuit terminal 14 and ground while commanding the Red Indicator
OFF with a scan tool.
• If 1 V or greater
1. Vehicle OFF/Ignition OFF, disconnect the X1 harness connector at the K73 Telematics Communication
Interface Control Module, vehicle in Service Mode/Ignition ON.
2. Test for less than 1 V between the control circuit terminal 14 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K73 Telematics Communication Interface Control Module.
5. Test for greater than 8 V between the control circuit terminal 14 and ground while commanding the Red
Indicator ON with a scan tool.
1. Vehicle OFF/Ignition OFF, disconnect the X1 harness connector at the K73 Telematics Communication
Interface Control Module.
2. Test for infinite resistance between the control circuit terminal 14 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the control circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K73 Telematics Communication Interface Control Module.
6. Test or replace the S48B Multifunction Switch - Overhead Console.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair procedure.
• Refer to Control Module References for control module replacement, programming and setup
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
Circuit/System Description
The telematics communication interface control module has the capability of commanding the horn, initiating door
lock/unlock, or operating the exterior lamps using the serial data circuits. These functions are commanded by the
OnStarA® Call Center per a customer request.
Diagnostic Aids
The customer concern may have been due to a lack of cellular service in a given area, or a failure in the National
Cellular Network infrastructure that has since been corrected.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
|
Circuit/System Verification | ||
|
1. Vehicle in Service Mode.
2. Verify that the horn, lights, and the door locks on the vehicle operate properly.
• If an applicable vehicle system does not operate properly
Refer to Diagnostic System Check - Vehicle .
• If all applicable vehicle systems operate properly
3. Verify that a call can be successfully placed to the OnStar Call Center by pressing the blue OnStar button.
• If unable to contact the OnStarA® call center
Refer to Unable to Contact OnStar Call Center
• If able to contact the OnStar Call Center
4. Verify with the OnStar advisor that all remote functions (door locks, lights, and horn) work.
• If the remote functions do not operate when requested
Replace the K73 telematics communication interface control module
• If the remote functions operate when requested
5. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for telematics communication interface control module replacement,
programming and setup.
ONSTAR BUTTON MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
|
Diagnostic Fault Information | ||||||||||||||||||||
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Circuit/System Description |
The OnStarA® button assembly consists of 3 buttons, Call/Answer, OnStarA® Call Center, and OnStarA®
Emergency. The telematics communication interface control module supplies the OnStarA® button assembly with 10
V via the keypad supply voltage circuit. Each of the buttons, when pressed, completes the circuit across a resistor
allowing a specific voltage to be returned to the telematics communication interface control module over the keypad
signal circuit. Depending upon the voltage range returned, the telematics communication interface control module is
able to identify which button has been activated.
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE: Contact the OnStarA® Call Center first before pressing the emergency button in
order to notify them of the test.
1. Vehicle in Service Mode.
2. Verify no DTCs are set.
• If any DTCs are set
3. Verify that each OnStarA® button operates normally by pressing each button individually.
• If none of the buttons operate normally
Refer to Circuit System Testing.
Test or replace the S48B Multifunction Switch - Overhead Console.
4. All OK.
Circuit/System Testing
1. Vehicle OFF and all vehicle systems OFF, disconnect the harness connector at the S48B Multifunction Switch
- Overhead Console. It may take up to 2 min for all vehicle systems to power down.
2. Test for less than 10 Q between the ground circuit terminal 5 and ground.
• If 10 fi or greater
1. Vehicle OFF.
2. Test for less than 2 Q in the ground circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, repair the open/high resistance in the ground connection.
3. Vehicle in Service Mode.
4. Test for 8.0 - 10.5 V between the 10 V reference circuit terminal 16 and ground.
1. Vehicle OFF, disconnect the harness connector at the K73 Telematics Communication Interface Control
Module.
2. Test for infinite resistance between the 10 V reference circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the 10 V reference circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K73 Telematics Communication Interface Control Module.
• If greater than 10.5 V
1. Vehicle OFF, disconnect the harness connector at the K73 Telematics Communication Interface Control
Module, vehicle in Service Mode.
2. Test for less than 1 V between the 10 V reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K73 Telematics Communication Interface Control Module.
• If between 8.0 - 10.5 V
5. Vehicle OFF.
6. Test for 500 - 900 Q between the signal circuit terminal 17 and ground.
1. Disconnect the X1 harness connector at the K73 Telematics Communication Interface Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K73 Telematics Communication Interface Control Module.
1. Disconnect the X1 harness connector at the K73 Telematics Communication Interface Control Module,
vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Vehicle OFF.
4. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K73 Telematics Communication Interface Control Module.
7. Test or replace the S48B Multifunction Switch - Overhead Console.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair procedure.
• Refer to Control Module References for control module replacement, programming and setup
Some vehicles equipped with the OnStarA® system have the capability of accessing voice mailboxes and other
automated phone systems by means of the steering wheel controls, while the OnStarA® Personal Calling feature is
in use. If the "Talk" or "Mute" button (depending upon the vehicle) on the steering wheel controls is depressed
during an OnStarA® Personal Calling call, the telematics communication interface control module receives the
message on the serial data bus from either the radio or body control module. This message is interpreted as a request
to turn any spoken numbers into dual tone multi-frequency tones to be delivered over the airwaves to the phone
system the user is communicating with. Complete instructions for operation of these features can be found in the
information provided to the customer with the OnStarA® system.
The steering wheel controls are a resistor network that consist of multiple momentary contact switches and a series
of resistors. The switches and resistor network are arranged so that each switch has a different resistance value.
When a switch is pressed, a voltage drop occurs in the resistor network, which produces a specific voltage value
unique to the switch selected, to be interpreted by either the radio or BCM. In the event the OnStarA® steering
wheel control functions are inoperative, technicians should refer to Steering Wheel Controls Malfunction , to begin
diagnosis of the steering wheel control concern.
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Antenna Signal Circuit Short to Ground
Antenna Signal Circuit Open Circuit
Antenna Signal Circuit Short to Battery
|
Diagnostic Fault Information | ||||||||||
| ||||||||||
|
Circuit/System Description |
The radio antenna for AM and FM radio reception is connected to the radio with a coaxial cable.
Conditions for Running the DTC
• Ignition ON/Vehicle in Service Mode.
• Battery voltage must be between 9 - 16 V
Conditions for Setting the DTC
The radio detects a short to ground in the antenna signal circuit center conductor.
The radio detects an open in the antenna signal circuit center conductor.
The radio detects a short to battery in the antenna signal circuit center conductor.
Action Taken When the DTC Sets
Radio reception may be poor or not available.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clears after 50 consecutive malfunction-free ignition cycles have occurred.
Diagnostic Aids
Poor AM and FM radio reception is dependent on multiple influences, some of which may not be vehicle related.
Areas which have high RF traffic or block the signal path may cause a degradation in radio reception. Radio
reception may also be influenced by items within the vehicle, but are not part of the radio system. Such examples are
aftermarket electrical accessories or other items which may generate noise in the vehicle electrical system.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Inspect the antenna for proper mounting or physical damage.
• If damage is found
Repair or replace as necessary
2. Ignition ON/Vehicle in Service Mode, A11 Radio ON.
3. Verify station reception is normal when tuned to several known good AM and FM stations.
• If AM or FM reception is poor.
Refer to Circuit/System Testing
4. All OK.
Circuit/System Testing
1. Ignition OFF/Vehicle OFF, disconnect the radio antenna coax cable from the A11 Radio and from the T2RR
Antenna - Roof Rear.
2. Verify the antenna coax cable passes the coax cable component test. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the antenna coax cable
3. Connect the antenna coax cable to the T2RR Antenna - Roof Rear.
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield at the radio
end of the coax cable.
Replace the radio antenna base.
5. Test for less than 10 Q between the coax cable outer shield and ground at the radio end of the coax cable.
• If 10 fi or greater
1. Clean the mounting surface of the radio antenna base.
2. Connect the antenna coax cable to the T2RR Antenna - Roof Rear.
3. Test for less than 10 Q between the coax cable outer shield and ground at the radio end of the coax
cable.
• If 10 Q or greater, replace the antenna base.
• If less than 10 Q, connect all harness connectors. Verify station reception is normal when tuned to
several known good AM and FM stations. If AM or FM reception concerns are still present,
replace the A11 Radio.
6. Test or replace the A11 Radio.
Component Testing
CAUTION: Refer to Test Probe Caution .
NOTE: Before testing the coax cable, check the cable exterior for being pinched, cut,
damaged, or having loose connections at the components, which can cause
reception issues.
To prevent false reading when testing the center coax terminals, use care not to
ground the test probe on the outer housing/shield.
1. Ignition OFF/Vehicle OFF, disconnect the coax cable at both components.
2. Test for less than 5 Q between coax cable center terminal end to end.
• If 5 fi or greater
Replace the coax cable
3. Test for less than 5 fi between the coax cable outer shield end to end.
• If 5 fi or greater
Replace the coax cable
4. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
Replace the coax cable
5. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• Refer to Control Module References for radio replacement, programming, and setup.
SPEAKER REPLACEMENT REFERENCE
|
Component |
Repair Instruction |
|
Front Center Speaker |
Radio Front Center Speaker Replacement |
|
Front Tweeter Speakers |
Radio Front Speaker Replacement |
|
Front Door Speakers |
Radio Front Side Door Speaker Replacement |
|
Rear Door Speakers |
Radio Rear Side Door Speaker Replacement |
|
Rear Subwoofer |
Radio Rear Compartment Speaker Replacement |
SPEAKER MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
|
Diagnostic Fault Information | |||||||||||||||||||||||||
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| |||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Circuit/System Description | |||||||||||||||||||||||||||||||||||||||||||||||||||||||
Each of the audio output channel circuits (+) and (-), at the radio and audio amplifier (if equipped) have a DC bias
voltage that is approximately one half of battery voltage. When using a DMM, each of the audio output channel
circuits will measure approximately 6.5 V DC. The audio being played on the system is produced by a varying AC
voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker
cone to move and produce sound. The frequency (Hz) of the AC voltage signal is directly related to the frequency of
the input (audio source playing) to the audio system. Both the DC bias voltage and the AC voltage signals are needed
for the audio system to properly produce sound.
Diagnostic Aids
• Improper speaker mounting or loose trim may cause an audible buzz or distortion. Inspect the appropriate
speaker and the surrounding interior trim for proper and secure mounting.
The EL-50334-6 Audio System Diagnostic CD contains audio tracks that can be used to duplicate and isolate
such concerns. Tracks 11 and 12 contain audio sweep tones for testing for speaker and grill rattles.
If the speaker or surrounding interior trim is found to be loose or improperly secured, correctly secure the item.
• When equipped with an amplifier, it is possible for some individual circuit faults to affect more than one
speakers operation. Perform diagnostic tests in the sequence listed to avoid misdiagnosis.
• The amplifier control circuit will measure less than 1 V when the mute function is OFF, and approximately 8
V DC when at full mute. When mute is active, the radio stops sending the varying AC voltage to the
amplifier/speakers.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-50334-50 USB Cable and Adapter Kit
Circuit/System Verification
Radio ON, Mute OFF, verify clear audio is heard from each audio speaker.
• If audio is inoperative from all speakers, replace the radio.
• If audio is inoperative from one or more, but not all, speakers or the audio emitted from the speakers is not
clear, refer to Speaker Circuit Malfunction - without Amplifier.
Radio ON, Mute OFF, verify clear audio is heard from each audio speaker.
• If audio is not heard from all speakers, or the audio emitted from the speakers is not clear, refer to Speaker
Circuit Malfunction- with Amplifier.
Circuit/System Testing
Speaker Malfunction - without Amplifier
NOTE: In the following tests, audio signal frequencies (Hz) will be tested. To prevent
misdiagnosis, the door chime must be OFF during testing. Ensure the driver
door latch is closed during testing.
1. Vehicle OFF, disconnect the harness connector at the appropriate P19 Speaker. Vehicle in Service Mode, radio
ON, mute OFF.
2. Test for 5 - 7 V between each audio signal circuit terminal 1 and terminal 2 and ground.
1. Vehicle OFF, disconnect the X1 harness connector at the A11 Radio.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the A11 Radio.
• If greater than 7 V
1. Vehicle OFF, disconnect the X1 harness connector at the A11 Radio. Vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the A11 Radio.
3. Insert the EL-50334-6 Audio Test CD from the EL-50334-50 USB cable and adapter kit. Play track number
three (50 Hz bass test tone) from the test CD.
4. Test for 49 - 51 Hz AC between each signal circuit terminal 1 and terminal 2 and ground.
Replace the A11 Radio.
5. Test or replace the P19 Speaker.
1. Vehicle OFF, disconnect the X1 harness connector at the T3 Audio Amplifier.
2. Test for less than 10 Q between the ground circuit terminal 8 and ground.
• If 10 fi or greater
1. Vehicle OFF.
2. Test for less than 2 Q in the ground circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, repair the open/high resistance in the ground connection.
3. Verify that a test lamp illuminates between the B+ circuit terminal 4 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Vehicle OFF.
2. Test for less than 2 Q in the B+ circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, refer to Power Mode Mismatch .
• If the test lamp does not illuminate and the circuit fuse is open
1. Vehicle OFF.
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the T3 Audio Amplifier.
4. Disconnect the X2 harness connector at the T3 Audio Amplifier.
5. Verify a test lamp does not illuminate between the control circuit terminal 14 and ground.
• If the test lamp illuminates
1. Disconnect the X1 harness at the A11 Radio.
2. Verify a test lamp does not illuminate between the control circuit and ground.
• If the test lamp illuminates, repair the short to voltage on the circuit.
• If the test lamp does not illuminate, replace the A11 Radio.
• If the test lamp does not illuminate
6. Vehicle in Service Mode, A11 Radio ON.
7. Verify a test lamp illuminates between the control circuit terminal 14 and ground.
• If the test lamp does not illuminate
1. Vehicle OFF. Disconnect the X1 harness at the A11 Radio.
2. Test for less than 2 Q in the control circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the A11 Radio.
• If the test lamp illuminates
8. Radio ON, mute ON.
9. Test for 7.5 - 8.5 V between the control circuit terminal 12 and ground.
• If greater than 8.5 V
1. Vehicle OFF, disconnect the X1 harness connector at the A11 Radio. Vehicle in Service Mode.
2. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the A11 Radio.
1. Vehicle OFF, disconnect the X1 harness connector at the A11 Radio.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the A11 Radio.
10. Radio ON, mute OFF.
11. Test for less than 1 V between the control circuit terminal 12 and ground.
• If greater than 1 V
Replace the A11 Radio.
12. Vehicle OFF, disconnect the X3 harness connector at the T3 Audio Amplifier.
13. Vehicle in Service Mode, A11 Radio ON.
14. Test for 5 - 7 V between the signal circuit terminals listed below and ground:
• Left front low level audio signal (+) terminal 14
• Left front low level audio signal (-) terminal 6
• Right front low level audio signal (+) terminal 5
• Right front low level audio signal (-) terminal 13
• Left rear low level audio signal (+) terminal 12
• Left rear low level audio signal (-) terminal 4
• Right rear low level audio signal (+) terminal 3
• Right rear low level audio signal (-) terminal 11
1. Vehicle OFF, disconnect the X1 harness connector at the A11 Radio.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the A11 Radio.
• If greater than 7 V
1. Vehicle OFF, disconnect the X1 harness connector at the A11 Radio. Vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the A11 Radio.
15. Insert the EL - 50334 - 6 Audio Test CD from the EL-50334-50 USB cable and adapter kit. Play track number
three (50 Hz bass test tone) from the test CD.
16. Test for 49 - 51 Hz AC between the audio signal circuit terminals listed below and ground:
• Left front low level audio signal (+) terminal 14
• Left front low level audio signal (-) terminal 6
• Right front low level audio signal (+) terminal 5
• Right front low level audio signal (-) terminal 13
• Left rear low level audio signal (+) terminal 12
• Left rear low level audio signal (-) terminal 4
• Right rear low level audio signal (+) terminal 3
• Right rear low level audio signal (-) terminal 11
Replace the A11 Radio.
17. Vehicle OFF, connect all harness connectors.
18. Disconnect the harness connector at the appropriate P19 Speaker. Vehicle in Service Mode, A11 Radio ON.
19. Test for 5 - 7 V between the appropriate signal circuit terminals listed below and ground:
• Door speaker or tweeter speaker signal (+): terminal 2
• Door speaker or tweeter speaker signal (-): terminal 1
• Subwoofer speaker signal (+) terminal B
• Subwoofer speaker signal (-) terminal A
1. Vehicle OFF, disconnect the X3 harness connector at the T3 Audio Amplifier.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the T3 Audio Amplifier.
• If greater than 7 V
1. Vehicle OFF, disconnect the X3 harness connector at the T3 Audio Amplifier. Vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the T3 Audio Amplifier.
• If between 5 - 7 V
NOTE: In the following tests, audio signal frequencies (Hz) will be tested. To prevent
misdiagnosis, the door chime must be OFF during testing. Ensure the driver
door latch is closed during testing.
20. Mute OFF, play track number three (50 Hz bass test tone) from the test CD.
21. Test for 49 - 51 Hz AC between the appropriate signal circuit terminals listed below and ground:
• Door speaker or tweeter speaker signal (+): terminal 2
• Door speaker or tweeter speaker signal (-): terminal 1
• Subwoofer speaker signal (+) terminal B
• Subwoofer speaker signal (-) terminal A
Replace the T3 Audio Amplifier.
22. Test or replace the P19 Speaker.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
• Refer to Control Module References for amplifier or radio replacement, programming and setup
UNABLE TO CONTACT ONSTAR CALL CENTER
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Cellular Phone Antenna Circuit Malfunction Short to Ground
Cellular Phone Antenna Circuit Malfunction Open Circuit
Circuit/System Description
The primary cellular phone antenna element is connected to the telematics communication interface control module
(violet connector) via a shielded coaxial cable. Cellular communication takes place on both the primary cellular
antenna signal circuit and the GPS/secondary cellular antenna signal circuit. This diagnostic only applies to the
primary cellular antenna signal circuit. Internal to the antenna on the cellular antenna signal circuit resistance is used
to apply a load, which the telematics communication interface control module uses to detect the presence of the
antenna.
Conditions for Running the DTC
• Ignition in the RUN or ACC position.
• System voltage is between 9.5 V and 15.5 V
• The above conditions are present for greater than 1 s.
Conditions for Setting the DTC
The telematics communication interface control module detects a short to ground on the primary cellular antenna
signal circuit.
• The telematics communication interface control module detects an open or high resistance on the primary
cellular antenna signal circuit.
• The above conditions are present for greater than 1 s.
Action Taken When the DTC Sets
The OnStarA® status LED turns red.
Conditions for Clearing the DTC
• The telematics communication interface control module detects the presence of a cellular antenna.
• A history DTC clears after 50 malfunction-free ignition cycles.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Special Tools
EL-49903-1 Test Antenna Navn-Cell Comn
|
Circuit/System Testing | ||
|
1. Ignition OFF/Vehicle OFF and all vehicle systems OFF, disconnect the violet primary cellular coax cable
connector at the K73 Telematics Communication Interface Control Module. It may take up to 2 min for all
vehicle systems to power down.
2. Using the EL-49903-1 Test Antenna Navn-Cell Comn connect the violet coax cable to the K73 Telematics
Communication Interface Control Module. Place the test antenna on the roof of the vehicle, ignition
ON/vehicle in Service Mode.
3. Verify the DTC does not set or a call can be completed to the OnStar Call Center while operating the vehicle
within the conditions for running the DTC.
• If the DTC sets or a call can not be completed to the OnStar Call Center
Replace the K73 Telematics Communications Interface Control Module.
• If the DTC does not set or a call can be completed to the OnStar Call Center
4. Ignition OFF/Vehicle OFF.
5. Disconnect the EL-49903-1 Test Antenna Navn-Cell Comn from the K73 Telematics Communication
Interface Control Module
6. Test the coax cable. Refer to Component Testing.
• If the coax cable does not pass the test
Replace the coax cable.
• If the coax cable passes the test
7. Test or replace the T2RR Antenna - Roof Rear.
Component Testing
CAUTION: Refer to Test Probe Caution
|
NOTE: |
|
Coax Cable Test
1. Test for less than 5 Q between the coax cable center terminal end to end.
• If 5 fi or greater
Replace the coax cable.
• If less than 5 fi
2. Test for greater than 5 Q between the coax cable outer shield end to end.
• If 5 fi or greater
Replace the coax cable.
• If less than 5 fi
3. Test for infinite resistance between the coax cable center terminal and the coax cable outer shield.
• If less than infinite resistance
Replace the coax cable.
• If infinite resistance
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair procedure.
• Refer to High Frequency Antenna Replacement
• Refer to Control Module References for telematics communication interface control module replacement,
setup, and programming
ONSTAR VOICE RECOGNITION MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
Circuit/System Description
The telematics communication interface control module is capable of interpreting voice commands received over the
cellular microphone circuits. Speech recognition allows the user to speak to one computer in the vehicle, and one
reached over the cellular communication network. The module attempts to understand the users command, and
responds by speaking back, or by taking the appropriate action, e.g. dialing the phone.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
|
Circuit/System Verification | ||
|
1. Vehicle in Service Mode.
2. Verify that your voice is heard clearly by the OnStar Call center.
• If your voice can not be heard clearly
Refer to OnStar Microphone Malfunction
3. Verify that the system responds appropriately to all voice commands by pressing the voice command button
and attempting to operate the system using multiple voice commands.
Replace the K73 Telematics Communication Interface Control Module
Refer to OnStar Description and Operation for tips on proper pronunciation
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair procedure.
Refer to Control Module References for telematics communication interface control module replacement,
programming and setup
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
|
Diagnostic Fault Information | ||||||||||||||||||||
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Circuit/System Description | ||||||||||||||||||||
When voice recognition for the infotainment system is started, voice signals from the cellular phone microphone are
passed through the telematics communication interface control module to the Human Machine Interface Control
Module via the voice recognition audio circuits.
Diagnostic Aids
• Refer to the Owners Manual and/or the Navigation System Owners Manual for voice recognition use and
commands.
• When the system recognizes the command the system will either perform the function or ask to confirm the
choice by clearly saying "yes" or "no".
• If experiencing difficulty with the system recognizing a command, confirm that the command is correct.
• Background noise such as a climate control fan positioned on high, open windows, or very loud outside noises,
can cause voice commands to be misunderstood.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify the OnStarA® voice recognition system is operating normally.
• If the OnStarA® voice recognition system is not operating normally.
Refer to OnStar Voice Recognition Malfunction.
• If the OnStarA® voice recognition system is operating normally.
2. Vehicle in Service Mode, infotainment system ON.
NOTE: Refer to the Owners Manual and/or the Navigation System Owners Manual for
voice recognition use and commands.
3. Begin voice recognition for the infotainment system and clearly speak one of the available commands.
4. Verify the infotainment system responds correctly to the command.
• If the infotainment system does not respond correctly to the command.
1. Clearly speak a different command.
2. Verify the infotainment system responds correctly to the command.
• If the infotainment system does not respond correctly to any commands, refer to Circuit/System
Testing.
• If the infotainment system responds correctly to the command.
3. Refer to the Owners Manual and/or the Navigation System Owners Manual for hints on speaking
commands.
• If the infotainment system responds correctly to the command.
5. All OK
Circuit/System Testing
1. Vehicle OFF, disconnect the X1 harness connector at the K74 Human Machine Interface Control Module.
2. Test for less than 10 Q between the low reference circuit terminal 2 and ground.
• If 10 fi or greater
1. Vehicle OFF, disconnect the X2 harness connector at the K73 Telematics Communication Interface
Control Module.
2. Test for less than 2 Q in the low reference circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K73 Telematics Communication Interface Control Module.
3. Vehicle OFF, disconnect the X2 harness connector at the K73 Telematics Communication Interface Control
Module. Vehicle in Service Mode.
4. Test for less than 1 V between the signal circuit terminal listed below and ground.
• Voice recognition audio signal terminal 6
• Voice recognition audio low reference terminal 12
• If 1 V greater
Repair the short to voltage on the circuit.
5. Vehicle OFF.
6. Test for infinite resistance between the signal circuits listed below and ground:
• Voice recognition audio signal terminal 6
• Voice recognition audio low reference terminal 12
Repair the short to ground on the circuit.
7. Test for less than 5 Q between the terminals listed below:
• K74 Human Machine Interface Control Module signal circuit terminal 1 X1 and the K73 Telematics
Communication Interface Control Module signal circuit terminal 6 X2
• K74 Human Machine Interface Control Module low reference circuit terminal 2 X1 and the K73
Telematics Communication Interface Control Module low reference circuit terminal 12 X2
• If 5 fi greater
Repair the open/high resistance in the circuit.
8. Replace the K74 Human Machine Interface Control Module. Connect all harness connectors.
NOTE: Refer to the Owners Manual and/or the Navigation System Owners Manual for
voice recognition use and commands.
9. Begin voice recognition for the infotainment system and clearly speak one of the available commands.
10. Verify the infotainment system responds correctly to the command.
1. Clearly speak a different command.
2. Verify the infotainment system responds correctly to the command.
• If the infotainment system does not respond correctly to any commands, replace the K73
Telematics Communication Interface Control Module.
11. All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for Human Machine Interface Control Module or Telematics Communication
Interface Control replacement, programming and setup.
REPAIR INSTRUCTIONS
 |
|
Fig. 9: Mobile Telephone Microphone Courtesy of GENERAL MOTORS COMPANY |
|
Callout |
Component Name |
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MOBILE TELEPHONE ANTENNA CABLE REPLACEMENT | ||||||
 |
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Fig. 10: Mobile Telephone Antenna Cable |
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HUMAN MACHINE INTERFACE CONTROL MODULE REPLACEMENT | ||||||
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Fig. 11: Human Machine Interface Control Module |
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COMMUNICATION INTERFACE MODULE REPLACEMENT | ||||||
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Fig. 12: Communication Interface Module |
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COMMUNICATION INTERFACE MODULE BATTERY REPLACEMENT |
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Fig. 13: Communication Interface Module Battery |
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COMMUNICATION INTERFACE MODULE BRACKET REPLACEMENT | ||||||
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Fig. 14: Communication Interface Module Bracket |
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RADIO REPLACEMENT | ||||||||
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Fig. 15: Radio Courtesy of GENERAL MOTORS COMPANY |
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RADIO CONTROL ASSEMBLY REPLACEMENT | ||||||
 |
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Fig. 16: Radio Control Assembly Courtesy of GENERAL MOTORS COMPANY |
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AUDIO DISC PLAYER AND USB RECEPTACLE REPLACEMENT | ||||||||
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Fig. 17: Audio Disc Player And USB Receptacle |
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RADIO SPEAKER AMPLIFIER REPLACEMENT | ||||||
 |
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Fig. 18: Radio Speaker Amplifier Courtesy of GENERAL MOTORS COMPANY |
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NAVIGATION SIGNAL SPLITTER REPLACEMENT | ||||||||
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Fig. 19: Navigation Signal Splitter Courtesy of GENERAL MOTORS COMPANY |
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TELEVISION ANTENNA CABLE REPLACEMENT | ||||||
 |
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Fig. 20: Television Antenna Cable Courtesy of GENERAL MOTORS COMPANY |
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MOBILE TELEPHONE ANTENNA COAXIAL CABLE REPLACEMENT | ||||||||
 |
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Fig. 21: Mobile Telephone Antenna Coaxial Cable |
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RADIO ANTENNA CABLE REPLACEMENT | ||||||
 |
|
Fig. 22: Radio Antenna Cable Courtesy of GENERAL MOTORS COMPANY |
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|
NAVIGATION ANTENNA COAXIAL CABLE REPLACEMENT (INLINE TO ONSTAR TO SPLITTER) | ||||||
 |
|
Fig. 23: Navigation Antenna Coaxial Cable (Inline To Onstar To Splitter) |
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NAVIGATION ANTENNA COAXIAL CABLE REPLACEMENT (ONSTAR TO SPLITTER) | ||||||
 |
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Fig. 24: Navigation Antenna Coaxial Cable (Onstar To Splitter) |
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NAVIGATION ANTENNA COAXIAL CABLE REPLACEMENT (SPLITTER TO HMI) | ||||||
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Fig. 25: Navigation Antenna Coaxial Cable (Splitter To HMI) |
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RADIO FRONT CENTER SPEAKER REPLACEMENT | ||||||
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Fig. 26: Radio Front Center Speaker Courtesy of GENERAL MOTORS COMPANY |
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RADIO FRONT SPEAKER REPLACEMENT | ||||||||
 |
|
Fig. 27: Radio Front Speaker Courtesy of GENERAL MOTORS COMPANY |
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HIGH FREQUENCY ANTENNA REPLACEMENT | ||||||||
 |
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Fig. 28: High Frequency Antenna Courtesy of GENERAL MOTORS COMPANY |
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RADIO FRONT SIDE DOOR SPEAKER REPLACEMENT | ||||||||
 |
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Fig. 29: Radio Front Side Door Speaker Courtesy of GENERAL MOTORS COMPANY |
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RADIO CONTROL SWITCH REPLACEMENT - STEERING WHEEL (LEFT SIDE REAR) | ||||||||
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Fig. 30: Radio Control Switch - Steering Wheel (Left Side Rear) |
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|
RADIO CONTROL SWITCH REPLACEMENT - STEERING WHEEL (RIGHT SIDE REAR) | ||||||||
 |
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Fig. 31: Radio Control Switch - Steering Wheel (Right Side Rear) |
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RADIO CONTROL SWITCH REPLACEMENT - STEERING WHEEL (RIGHT SIDE FRONT) | ||||||||||
Fig. 32: Radio Control Switch - Steering Wheel (Right Side Front)
Courtesy of GENERAL MOTORS COMPANY
|
Callout |
Component Name |
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Preliminary Procedure Remove Steering Wheel Spoke Cover. Refer to Steering Wheel Spoke Cover Replacement | |
|
1 |
Radio Control Switch Bolt (Qty: 2) CAUTION: Refer to Caution . Tighten 1.5 N.m (13 lb in) |
|
2 |
Radio Control Switch - Right Side Front Procedure Remove the radio control switch from the steering wheel spoke cover. |
RADIO CONTROL SWITCH REPLACEMENT - STEERING WHEEL (LEFT SIDE LOWER)
Removal Procedure
1. Remove Steering Wheel Spoke Cover. Refer to Steering Wheel Spoke Cover Replacement
 |
|
Fig. 33: Steering Wheel Spoke Lower Cover |
2. Remove Steering Wheel Spoke Lower Cover (1)
1. Use a flat bladed plastic tool to remove.
2. Disconnect the electrical connector.
 |
|
Fig. 34: Radio Control Switch And Bolts Courtesy of GENERAL MOTORS COMPANY |
3. Remove Radio Control Switch Bolts (1) (Qty: 2)
4. Remove Radio Control Switch - Left Side Lower (2) @ Steering Wheel Spoke Lower Cover
Installation Procedure
 |
|
Fig. 35: Radio Control Switch And Bolts Courtesy of GENERAL MOTORS COMPANY |
1. Install Radio Control Switch - Left Side Lower (2) @ Steering Wheel Spoke Lower Cover
CAUTION: Refer to Fastener Caution .
2. Install and tighten Radio Control Switch Bolts (1) (Qty: 2) to 1.5 N.m (13 lb in)
 |
|
Fig. 36: Steering Wheel Spoke Lower Cover Courtesy of GENERAL MOTORS COMPANY |
3. Install Steering Wheel Spoke Lower Cover (1)
4. Install Steering Wheel Spoke Cover. Refer to Steering Wheel Spoke Cover Replacement
RADIO REAR SIDE DOOR SPEAKER REPLACEMENT
 |
|
Fig. 37: Radio Rear Side Door Speaker Courtesy of GENERAL MOTORS COMPANY |
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|
RADIO REAR COMPARTMENT SPEAKER REPLACEMENT | ||||||||
 |
|
Fig. 38: Radio Rear Compartment Speaker |
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Callout |
Component Name |
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Preliminary Procedure Remove Quarter Lower Rear Trim Panel (Right Side). Refer to Quarter Lower Rear Trim Panel Replacement (Right Side) | |
|
1 |
Radio Rear Compartment Speaker Fastener (Qty: 3) CAUTION: Refer to Caution . Tighten 6 N.m (53 lb in) |
|
2 |
Radio Rear Compartment Speaker Procedure
|
DESCRIPTION AND OPERATION
This OnStarA® system consists of the following components:
• Telematics communication interface control module
• OnStarA® three button assembly
• Microphone
• Cellular antenna
• Navigation antenna
• BluetoothA® antenna (If equipped)
• Back up battery (If equipped)
• WiFi Hotspot (If equipped)
• TTY (Teletypewriter)
This system also interfaces with the factory installed vehicle audio system.
|
1 C3 ■ Telematics Communication I Interface "I B24 ■ Cellular 1 Phone I Microphone 1 S51 I Telematics 1 Button I Assembly 1 T4G ■ Cellular ’ Phone. I Navigation. |
 |
 |
I Telematics I Interface Control Module |
Fig. 39: OnStar System Block Diagram
Courtesy of GENERAL MOTORS COMPANY
Callout
Component Name
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|
Telematics Communication Interface Control Module |
The OnStar Generation 10 system uses Global System for Mobile Communication (GSM) to communicate data and
voice signals over the national cellular network. The module may also have the ability to act as a Wireless Local
Area Network (WLAN) Wi-Fi hotspot similar to a home wireless router. The module houses an internal WLAN
antenna enabling hotspot connectivity and streaming high speed media to the entertainment system. The module also
may enable Teletypewriter (TTY) and be capable of Bluetooth communication utilizing an internal antenna. The
module is capable of up to 4G LTE speeds and houses 2 technology systems, one to process Global Positioning
System (GPS) data, and another for cellular information. The module sends and receives all cellular communications
over two cellular antennas and cellular antenna coax cables.
The OnStar Gen 10 system has two antenna inputs, a primary cellular signal and a combined GPS/secondary cellular
signal. The OnStarA® system uses the United States Global Positioning System (GPS) signals to provide location on
demand. GPS is a space-based satellite navigation system that provides location and time information in all weather
conditions, anywhere on or near Earth where there is an unobstructed line of sight to four or more GPS satellites.
The module also has the capability of activating certain features such as, the horn, remote starting, initiating door
lock/unlock, or activating the exterior lamps using the serial data circuits. These functions can be commanded by the
OnStarA® Call Center per a customer request or mobile device app depending on vehicle and customer subscription.
Dedicated circuits are used to connect the telematics communication interface control module to a microphone, the
button assembly, radio, and if equipped the Back Up Battery (BUB). The telematics communication interface control
module communicates with the rest of the vehicle over the serial data bus.
Power is provided by a dedicated, fused B+ circuit. Ground is provided through the vehicle wiring harness attached
to the module. The power mode state is determined by the telematics communication interface control module
through serial data messaging.
OnStarA® Three Button Assembly
• The OnStarA® button assembly may be part of the rearview mirror, or a separate, stand alone unit. The button
assembly is comprised of 3 buttons or 3 capacitive touch buttons and status LED's or an error indicator. The
buttons are defined as follows:
• The answer/end button, which is black with a white phone icon or a white driver figure seated with voice
signals near its face, allows the user to answer and end calls or initiate speech recognition.
• The blue OnStarA® call center button, which displays the OnStarA® logo, allows the user to connect to
the OnStarA® call center.
• The emergency button, which displays white letters "SOS" with red background, sends a high priority
emergency call to the OnStarA® call center when pressed.
If the LED does not illuminate, this may indicate that the customers OnStarA® subscription is not active or has
expired. Push the blue OnStar button to connect to an advisor who can then verify the account status.
The telematics communication interface control module supplies 10 volts to the OnStarA® button assembly on the
keypad supply voltage circuit. When pressed, each button completes a circuit across a resistor allowing a specific
voltage to be returned to the telematics communication interface control module on the keypad signal circuit.
Depending upon the voltage range returned the telematics communication interface control module is able to identify
which button has been pressed.
The OnStarA® status LED or error indicator is located near the buttons. The LED is green when the system is ON
and operating normally. When any indicator is illuminated and flashing, it is an indication that a call is in progress.
When the LED is red, this indicates a system malfunction is present. In the event there is a system malfunction and
the OnStarA® system is still able to make a call, the LED will flash red during the call.
Each LED or error indicator is controlled by either the telematics communication interface control module over
dedicated LED signal circuits or by low speed GMLAN serial data depending on the inside rearview mirror option.
Ground for the LED is provided by the wiring harness attached to the button assembly.
Secondary OnStarA® Controls
Some vehicles may have an additional button that when pushed can engage the OnStarA® system. The button may
be a symbol of a face with sound waves, or may say MUTE, or be a symbol of a radio speaker with a slash through
it.
By engaging the OnStarA® system with this feature, the user can interact with the system by use of voice
commands. A complete list of these commands is supplied in the information provided to the customer. If the
information is not available for reference, at any command prompt the user can say "HELP" and the telematics
communication interface control module will return an audible list of available commands.
OnStarA® Microphone
The cellular microphone can be part of the rearview mirror assembly, or a stand-alone unit in the headliner or roof
console. In either case, the telematics communication interface control module supplies approximately 10V to the
microphone on the cellular microphone signal circuit. The microphone modifies the 10V depending on the volume
and voice being detected. A cellular microphone low reference circuit or a drain wire provides a ground for the
microphone. The microphone signal circuits pass through the telematics communication interface control module to
support entertainment voice recognition.
Cellular and GPS Antennas
The combination antenna will have any of the following antenna elements when equipped with OnStar:
• Primary cellular element
• Secondary cellular element
• GPS element
• Digital radio element
• AM/FM element
The Gen 10 OnStarA® system uses 2 cellular antenna elements to send and receive cellular data, the primary cellular
element and the secondary cellular element. The primary cellular signal is carried by a coax cable that connects the
antenna directly to the telematics communication interface control module. Details of the secondary cellular signal
are further described below.
The GPS antenna element is used to collect the signals of the orbiting GPS satellites. Within the antenna is housed a
low noise amplifier that allows for a more broad and precise reception of this data. Also housed within the antenna is
circuitry to combine the GPS signal and the secondary cellular signal. Without navigation, the combination
GPS/secondary cellular signal is carried by a coax cable that connects directly to the telematics communication
interface control module. The cable also provides a path for DC current for powering the antenna. With navigation,
the combination GPS/secondary cellular signal is carried by a coax cable that connects to the navigation signal
splitter. The splitter supplies the GPS signal to the navigation/entertainment system and the GPS/cellular signal to the
telematics communication interface control module.
The digital radio element collects digital radio signals from two satellites and where necessary terrestrial repeaters.
The digital radio signal is carried by a coax cable and connected to the digital radio receiver. Refer to Radio/Audio
System Description and Operation for further details.
The radio signal is sent from a broadcast station and is then received by the AM/FM radio antenna element. The
AM/FM radio signal is carried by a coax cable and is connected to the radio. Refer to Radio/Audio System
Description and Operation for further details.
OnStarA® RemoteLink
OnStarA® RemoteLink is a mobile app to link mobile devices to a vehicle for limited diagnostics and feature
controls. After downloading the app and registering the device, vehicle owners with an eligible vehicle can use their
mobile devices to access real-time data from their vehicle and perform specific commands remotely.
All communication between the app and the vehicle is powered by OnStar'sA® advanced connected vehicle
technology. An active OnStarA® account as well as a valid OnStarA® username and password are required to use
the app. The remote commands must be enabled by logging into the user's OnStarA® account prior to using the app.
Refer to the owners manual for available vehicle data and control features.
Compass Heading
The telematics communication interface module has a compass feature to calculate vehicle direction which is
displayed via the instrument panel cluster or designated display. The compass heading is determined by dead
reckoning until the GPS 3d fix is established. The dead reckoning is accomplished by using the yaw rate sensors and
wheel ticks to determine heading changes from a GPS known heading. The GPS 3d fix heading is determined by the
deferential of two locations. If "CAL" is displayed on the Instrument Panel Cluster or designated display refer to the
owners manual for steps to calibrate the compass.
BluetoothA® (If Equipped)
BluetoothA® wireless technology is a short-range communications technology intended to replace the cables
connecting portable and/or fixed devices while maintaining high levels of security. Only vehicles with steering wheel
controls will have BluetoothA® functionality. In order to utilize the vehicle's BluetoothA® system, a BluetoothA®
equipped cellular phone is required.
The BluetoothA® antenna is internal to the telematics communication interface control module, radio or human
machine interface module and is used to send and receive signals from a BluetoothA® enabled cellular phone. The
available features and functions are determined by the software within the device being used and the telematics
communication interface control module. The operating range of the signal from the vehicle is approximately 30
feet. Note that the operating range is dependent upon the cellular phone being used and battery level of the phone.
With BluetoothA® technology customers can experience hands-free calling as their BluetoothA® capable cellular
phones are wirelessly connected to the vehicle. It will allow customers to place and receive calls using the steering
wheel controls and voice recognition. The vehicle audio system will allow you to listen to your call through the
vehicle speakers and adjust volume through steering wheel or radio controls.
Not all BluetoothA® cellular phones are guaranteed to work with the vehicle's BluetoothA® system. Based on the
cellular phone's service provider and the manufacturer's implementation of BluetoothA®, not all phones support all
available BluetoothA® functionality. BluetoothA® enabled cellular phones will be tested for vehicle compatibility
and a feature compatibility list will be provided via the GM BluetoothA® website: http://www.gm.com/vc/bluetooth/
BluetoothA® Features Supported
The following is a list of features supported by the BluetoothA® system. Note that not all devices will support all of
the listed functions.
• Automatic reconnection - highest priority phone will automatically be connected to vehicle when vehicle
ignition is on
• Hands-free dialing- via digits, redial, name tags (phone number saved to a nametag via voice recognition)
• Answering a call
• Ending a call
• Mute a Call
• Rejecting a call - ignore an incoming call
• Call Waiting
• Three-way Calling - initiated from hands-free system
• Send Number During a Call - this is used when calling a menu-driven phone system
• Transfer a Call - transfer call from vehicle to cellular phone and visa versa
• Voice Pass-Thru - allow access to the voice recognition commands on the cellular phone
Pairing a BluetoothA® Cellular Phone to the Vehicle
In order to use hands-free calling, the cellular phone must be paired to the vehicle. Up to five devices can be paired
to the vehicle at one time, but only one can be connected at any given time. To pair a phone, the customer must know
how to operate the BluetoothA® functionality of their phone. The pairing process must only be done one time for
each phone, unless that phone's information is deleted. The system will always generate a password and will provide
that password if the device you are pairing does not support Secure Simple Pairing (SSP). If the device being paired
does support SSP the system will not provide the password and automatically pair the device. For safety reasons, the
pairing process is disabled while the vehicle is moving.
Once the BluetoothA® cellular phone has been paired with vehicle, it will automatically connect to the vehicle when
the ignition is on and the device is on. When more than one paired phone is in the vehicle, the phone with the highest
priority will be connected. If the cellular phone is in use while getting into the vehicle, the phone can be switched to
hands-free mode with the press of a button. In addition, a call in progress can be transferred from the vehicle hands-
free mode to the phone to continue the call as the customer exits the vehicle.
Complete pairing instructions are provided in the Vehicle Owners Manual.
Back-up Battery (If Equipped)
NOTE: Do not disconnect the main vehicle battery or remove the OnStarA® fuse with the
ignition key in any position other than OFF. Disconnecting power to the OnStarA®
module in any way while the ignition is ON or with retained accessory power
activated may cause activation of the OnStarA® Back-Up Battery. This action is per
design as the back-up battery is designed to provide power to the telematics
communication interface control module so an emergency notification call can be
made after an event where the main battery is disabled. Once the Back-Up Battery is
activated it will stay on until the power is restored back to the telematics
communication interface control module. The telematics communication interface
control module naturally chooses the main supply voltage as it's default supply, but
if the main supply is removed or lost for any reason the OnStarA® module will use
the Back-Up Battery as a power supply as long as the default supply can not be
detected. The back-up battery is not rechargeable and once discharged below 9.5
volts the back-up battery must be replaced.
Certain OnStarA® equipped vehicles may also be equipped with a back-up battery. The back-up battery is a non-
rechargeable, lithium battery intended to provide an auxiliary power source for the telematics communication
interface control module in the event where power from the main vehicle battery is lost.
The back-up battery is intended to have a limited life span of approximately 4 years and is designed to maintain an
open circuit voltage between 16 V and 9 V throughout this period. This allows the battery to power the basic
functions of the telematics communication interface control module for least one 200 second (5 minute) call at the
end of the 4 year span, should the main vehicle battery be lost. In the case of a vehicle losing vehicle battery power,
OnStar will switch over to the backup battery based on an internal algorithm. It will look for an air-bag deploy, or
near-deploy, messages from the SDM. If there are no messages the OnStar module will stay wake for a few minutes
longer and monitor the buttons in the mirror. If not pressed, the modules will power down and shut off completely.
The back-up battery is connected to the telematics communication interface control module through the back-up
battery positive voltage circuit and back-up battery ground circuit and is protected from a short circuit by means of
an internal fuse. In the event the back-up battery, battery positive voltage circuit is shorted to the back-up battery
ground circuit or chassis ground, the fuse will open and render the back-up battery permanently inoperable. The
status of the back-up battery and its associated wiring is monitored by the telematics communication interface
control module.
WiFi Hotspot
The telematics communication interface control module acts as a Wireless Local Area Network (WLAN) WiFi
hotspot router and uses direct 4G LTE connectivity to the internet. It has the ability to connect up to 7 devices at one
time. A data plan is required and when purchased, a security default password is established. There are several ways
to change the SSID or password, by placing a call to the OnStar Call Center, by using the Gen 10 mobile app or
through the scan tool.
The system utilizes a secure autoconnect feature between the telematics communication interface control module and
the radio/HMI. No user interaction is required, it is always available and ready to connect to a dedicated in car
device. The ignition must be in Run, Accessory or RAP for WiFi to operate.
Audio System Interface
When the OnStarA® requires audio output, a serial data message is sent to the audio system to mute all radio
functions and transmit OnStarA® originated audio. The OnStarA® audio is transmitted to the vehicle audio system
by a dedicated signal circuit and a low reference circuit.
The audio system will mute and an audible ring will be heard though the speakers if the vehicle receives a call with
the radio ON.
On some vehicles, the HVAC blower speed may be reduced when the OnStarA® system is active to aid in reducing
interior noise. When the system is no longer active, the blower speed will return to its previous setting.
OnStarA® Sleep Cycle
The OnStarA® system uses a unique sleep cycle to allow the system to receive cellular calls while the ignition is in
the OFF position and retained accessory power mode has ended. This cycle enables the telematics communication
interface control module to perform remote functions, such as door unlock, as commanded over the air by the
OnStarA® Call Center, and to continue to maintain an acceptable level of battery electrical drain.
The OnStarA® system uses 4 states of readiness, depending upon the type of cellular market the vehicle is in when
the ignition is put into the OFF state:
• High power
• Low power
• Sleep
• Digital standby
The high power state is in effect whenever the ignition is in the ON or RUN position, or retained accessory power is
enabled, and the OnStarA® system is sending or receiving calls or when the system is performing a remote function.
The low power state is in effect when the OnStarA® system is idle with the ignition in the ON or RUN position, or
with retained accessory power enabled.
The sleep state is entered after the vehicle has been shut off and the retained accessory power has timed out while in
an analog cellular area. At a predetermined time recorded within the telematics communication interface control
module, the system re-enters the low power state to listen for a call from the OnStarA® Call Center for 1 minute.
After this interval, the system will again return to the sleep state for 9 minutes. If a call is sent during the 1 minute
interval, the OnStarA® system will receive the call and immediately go into the high power mode to perform any
requested functions. If no call is received during the 1 minute interval, the system will go back into the sleep mode
for another 9 minutes. This process will continue for up to 48 hours, after which the OnStarA® system will turn off
until the ignition is turned to the ON or RUN position.
The digital standby power state is entered after the vehicle has been shut off and the retained accessory power has
timed out while in a digital cellular area. When in digital standby mode, the OnStarA® module is able to perform all
remote functions as commanded by an OnStarA® advisor at any time, for a continuous 120 hours. After 120 hours,
the OnStarA® module will go into sleep mode until a wake up signal from the vehicle is seen by the telematics
communication interface control module. If the OnStar module loses the digital cellular signal it will revert to analog
mode and follow the standard sleep state (9 minutes OFF, 1 minute standby) based on the time of the GPS signals,
this will continue until a digital cellular signal is again received.
If the OnStarA® system loses battery power while the system is in a standby or sleep mode, the system will remain
OFF until battery power is restored and the ignition is turned to the ON or RUN position.
Features
The hands free, OnStarA® personal calling cellular phone feature is an additional feature of the OnStarA® system.
This feature is embedded within the telematics communication interface control module; however it must be
activated by an OnStarA® advisor. OnStarA® personal calling operates similar to most hand held cellular phones in
that the availability for its usage is based on minutes or units. The customer must have a current OnStarA®
subscription, as this feature cannot be utilized without it. To use OnStarA® personal calling, the customer must also
purchase units (minutes) as outlined in the owners guide provided with the OnStarA® system. Units begin to deplete,
1 unit is equal to 1 minute, as the customer makes outbound phone calls, answers inbound phone calls, or while
connected to the OnStarA® virtual advisor. In addition, units may also have an expiration date, depending upon the
type of units purchased.
Customers have the ability to store telephone numbers within the module, referenced by a nametag for the
convenience of frequently dialed numbers. After storing a nametag, the user can dial this number by initiating the
OnStarA® personal calling feature, speaking the word "call," and repeating the nametag assigned.
Turn by Turn Navigation allows the driver to contact OnStarA® to obtain directions for driving from a current
location to a desired location. The Turn by Turn Navigation system stores your planned route and continually checks
your position along that route, when you deviate from the planned route, the system will recognize this and prompt
the driver with verbal prompts for how to proceed. The driver then responds verbally to direct the system to continue
the current routing or to recalculate the route because of a missed turn.
The Advisor Record Feature allows the user to store any information given during a call with an OnStarA® Advisor.
Recording is activated by pressing the blue OnStar button during a call; pressing the button a second time stops the
recording. The stored information can be played back by pressing the phone button on the three button assembly and
using the voice command "Advisor Playback".
Teletypewriter (TTY) Users
OnStar has the ability to communicate to deaf, hard-of-hearing, or speech-impaired customers while in the vehicle.
The available dealer-installed TTY system can provide in-vehicle access to all of the OnStar services, except Virtual
Advisor and OnStar Turn-by-Turn Navigation.
Deactivated OnStarA® Accounts
In the event a customer has not renewed their OnStarA® account after expiration or the account was never activated,
OnStarA® will make a discrete cellular call to the vehicle to deactivate the OnStarA® system. Before taking this
action, customers are notified that the OnStarA® system in their vehicle will be deactivated unless they elect to
renew the account. After the OnStarA® account has been deactivated, customers will experience the following:
• The OnStarA® status LED will not illuminate.
• The OnStarA® system will NOT attempt to connect to the OnStarA® Call Center in the event of a collision or
if the vehicle's front air bags deploy for any other reason.
• An emergency button press will play a demo message indicating the service has been deactivated.
• An OnStarA® Call Center button press will connect the customer with a dedicated sales team who can sell an
OnStarA® subscription and reactivate the vehicle. Depending on the type of OnStarA® hardware in the
vehicle, the customer may first hear a demonstration message stating there is no current OnStarA®
subscription for the vehicle, and directing the customer what to do to activate services.
• OnStarA® personal calling will not be available, as this feature requires the customer to have a current
OnStarA® account. Attempts to use this feature may result in cellular connection failure messages and the
inability to connect to the number dialed.
Certain vehicles that have never had an active OnStarA® account, or that have been deactivated, may be unable to
establish a connection with the OnStarA® Call Center. When normal published diagnostic procedures do not indicate
a possible cause for the no connect concern, the vehicle may have been deactivated. For deactivated vehicles, a no
connect response should be considered normal operation. Further diagnosis and subsequent repair is only necessary
should the customer elect to become an active OnStarA® subscriber or renew the account subscription.
OnStarA® Cellular, GPS, and Diagnostic Limitations
The proper operation of the OnStarA® System is dependent on several elements outside the components integrated
into the vehicle. These include the National Cellular Network Infrastructure, the cellular telephone carriers within the
network, and the GPS.
The cellular operation of the OnStarA® system may be inhibited by factors such as the users range from an analog or
digital cellular tower, the state of the cellular carrier's equipment, and the location where the call is placed. Making
an OnStarA® key press in areas that lack sufficient cellular coverage or have a temporary equipment failure will
result in either the inability of a call to complete with a data transfer or the complete inability to connect to the
OnStarA® Call Center. The OnStarA® system may also experience connection issues if the identification numbers
for the module, station identification number, electronic serial number or manufacturers electronic ID, are not
recognized by the cellular carriers local signal receiving towers.
The satellites that orbit earth providing the OnStar system with GPS data have almost no failures associated with
them. In the event of a no GPS concern, the failure will likely lie with the inability of the system to gain GPS signals
because of its location, i.e. in a parking structure, hardware failure, or being mistaken with an OnStarA® call which
has reached the Call Center without vehicle data.
During diagnostic testing of the OnStarA® system, the technician should ensure the vehicle is located in an area that
has a clear unobstructed view of the open sky, and preferably, an area where analog or digital cellular calls have been
successfully placed. These areas can be found by successfully making an OnStarA® keypress in a known good
OnStarA® equipped vehicle and confirming success with the OnStarA® Call Center advisor. Such places can be
used as a permanent reference for future OnStarA® testing.
Mobile Identification Number and Mobile Directory Number
The telematics communication interface control module utilizes 2 numbers for cellular device identification, call
routing and connection, a mobile identification number and a mobile directory number. The mobile identification
number represents the number used by the cellular carrier for call routing purposes while the mobile directory
number represents the number dialed to reach the cellular device.
Operation of the OnStarA® Speech Recognition Systems
OnStarA® users communicate with 2 speech recognition systems. Speech recognition allows the user to speak to one
computer in the vehicle, and one reached over a phone line. The computer tries to understand the users command,
and responds by speaking back, or by taking the appropriate action, e.g. dialing the phone.
• Personal Calling uses a speech recognition system that resides in the vehicle. When the user presses the phone
button, the system states, Ready, and listens for the user's command. The user can speak commands to control
the hands-free phone.
• Virtual advisor is a remote speech recognition system that the caller can access by making a phone call. The
user connects to virtual advisor by requesting it during personal calling use. The user is then transferred to the
virtual advisor server and talks to it via a cellular connection.
The OnStarA® speech recognition systems use speech technology that is designed to understand a wide range of
American English speakers. Although there is no one right way to speak English, the system will work best when
users try to modify their pronunciation should they encounter difficulty. Users who do not obtain good results are
advised to try the tips and workarounds found in the Infotainment System Manual or the Owners Manual.
The entertainment system on this vehicle may have several different configurations available to it. To determine the
specific configuration of the vehicle, please see the Service Parts ID Label, and refer to RPO Code List .
Each item in the list below represents topics covered in detail below.
• Radio Circuit Operation
• Information Display and Controls
• Antenna System
• Radio Reception
• Speaker Operation
• Audio Amplifier (If equipped)
• Theft Deterrent
• Auxiliary Audio Input Jack (If equipped)
• USB Port (If equipped)
• BluetoothA® (UP9) (if equipped)
• Applications (if equipped)
• Navigation System Components and Features (if equipped)
• OnStarA® (if equipped)
• Steering Wheel Controls (If equipped)
• Auto Volume Control
Radio Circuit Operation
The radio does not use a discrete ignition feed circuit for power moding. The power mode master provides the
system power mode to the radio via serial data messages. The power mode master determines the system power
mode by processing power mode information from ignition switch inputs. Serial data power modes supported by the
radio are OFF, ACCESSORY, RUN, and CRANK REQUEST.
The vehicle harness provides a ground for the radio circuits. The radio may also be case grounded.
The radio communicates with other modules via serial data.
Each of the audio output channel circuits (+) and (-), at the radio have a DC bias voltage that is approximately one
half of battery voltage. The audio being played on the system is produced by a varying AC voltage that is centered
around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and
produce sound. The frequency (Hz) of the AC voltage signal is directly related to the frequency of the input (audio
source playing) to the audio system. Both the DC bias voltage and the AC voltage signals are needed for the audio
system to properly produce sound.
The remote enable circuit is a discrete 12 V signal supplied to infotainment system components when the radio is
producing audio, needs the front display on, needs video entertainment system components on, or needs to produce
chimes. This signal is used to control the power state of the components. There is no output on radio the remote
enable circuit when the vehicle is in the CRANK powermode, this is to minimize current consumption from the
attached modules and also to avoid audio pops during crank events.
|
Information Display and Controls |
 |
|
Fig. 40: Navigation Radio Communications Flow Diagram |
|
Callout |
Component Name |
|
1 |
Radio/HVAC Controls |
|
2 |
Info Display Module |
|
3 |
Radio |
|
4 |
HVAC Control Module |
|
5 |
Data Link Connector |
|
a |
GMLAN |
|
b |
Local Interconnect Network |
|
c |
CAN Graphical Interface |
|
d |
Digital Video |
|
e |
Touch Screen Serial Data |
The info display module has continuous power and ground. When the radio is on, a discrete 12 V signal is supplied
on the remote enable circuit to the color display module. This signal is used to control the power state of the module,
which is active when the signal is high and inactive when the signal is low.
The info display module receives digital video data from the radio for on-screen display information through a
dedicated video cable. The radio communicates with the info display module over the touch screen serial data
circuits for touch screen inputs and backlighting dimming level.
The radio controls communicate radio control inputs directly to the radio through the CAN Graphical Interface (CGI)
data circuits. After receiving the message the radio will perform the requested function. Messages communicated
between the radio and the radio/HVAC controls include the following:
• Button presses/knob rotations
• Commands for the state of indicators
• Radio control back-lighting
The HVAC controls are a separate component from the radio controls. HVAC data for controls and status indicators
is communicated between the HVAC controls and the HVAC control module with a separate LIN serial data circuit.
HVAC status screen information from the HVAC control module is transmitted to the radio on the GMLAN serial
data circuit. The radio then displays the desired screen information on the info display using the video data circuits.
Antenna System
The multi-band antenna is located on the roof of the vehicle. This type of antenna may be used with the AM/FM
radio, but is primarily for OnStarA® cellular and GPS signals and the XM™ Satellite Radio Service System, if the
vehicle has these features. Keep this antenna clear of snow and ice build up for clear reception. If the vehicle has a
sunroof, the performance of the system may be affected if the sunroof is open. Loading items onto the roof of the
vehicle can interfere with the performance of the system, ensure the multi-band antenna is not obstructed.
The radio provides battery voltage to the AM/FM amplifier in the antenna base using the center conductor of the
antenna coaxial cable. When a 12 V signal is seen by the amplifier, both AM and FM signals are amplified.
Radio Reception
The radio signal is sent from a broadcast station and is then received by an antenna. The strength of the signal
received depends on the following:
• The power output (wattage) of the broadcasting station
• The location of the vehicle (or receiver) relative to the broadcast tower.
• Height of the broadcast antenna
• Height of the receiving antenna
• Obstacles between the tower and the receiver
• Atmospheric conditions
• What band (AM or FM) the station is broadcasting
• Type of antenna and the ground plane
The XM satellite receiver is integrated into the radio. XM satellite radio provides digital radio reception. The XM
signal is broadcast from two satellites and, where necessary, terrestrial repeaters. The high power satellites allow the
antenna to receive the XM signal even when foliage and other partial obstructions block the antennas view of the
satellite. Terrestrial repeaters are used in dense urban areas. These repeaters will receive the satellite signal and re-
broadcast them at much higher power levels in order to ensure reception in areas with densely packed tall buildings.
A service fee is required in order to receive the XM service.
Radio Data System (RDS)
The RDS feature is available only on FM stations that broadcast RDS information. This system relies upon receiving
specific information from these stations and only works when the information is available. While the radio is tuned
to an FM-RDS station, the station name or call letters display. RDS data is carried in what is known as a "subcarrier".
A subcarrier is a frequency that the FM broadcaster is authorized to use to send data that is not audible in the main
audio program.
RDS functions will only work with FM broadcast stations that are broadcasting RDS data. Not all FM Broadcast
stations broadcast RDS data or offer all of the RDS services.
The information displayed is dependent upon the information broadcast by the particular station. The information
may vary greatly between stations. RDS functions may not work properly when reception is weak, reception is of
poor quality, or RDS is not implemented properly by the FM Broadcaster. In some cases, a radio station broadcasting
incorrect information may cause the RDS features of the radio to appear to work improperly.
With RDS, the radio can do the following:
• Display text information such as: station identification, type of programming, and general information (artist
and song title, station messages, call in phone numbers, etc.).
• Seek to stations broadcasting the selected type of programming
• Receive announcements concerning local and national emergencies
• Receive alert warnings of local or national emergencies. When an alert announcement comes on the current
radio station, ALERT! displays. You will hear the announcement, even if the volume is low or a CD is playing.
If a CD is playing, play stops during the announcement. Alert announcements cannot be turned off. ALERT! is
not affected by tests of the emergency broadcast system. This feature is not supported by all RDS stations.
Speaker Operation
Speakers turn electrical energy into mechanical energy to move air, using a permanent magnet and an electromagnet.
The electromagnet is energized when the radio or amplifier (if equipped) delivers current to the voice coil on the
speaker. The voice coil will form a north and south pole that will cause the voice coil and the speaker cone to move
in relation to the permanent magnet. The current delivered to the speaker is rapidly changing alternating current
(A/C). This causes the speaker cone to move in two directions producing sound.
Audio Amplifier (If equipped)
A fused battery voltage circuit provides the main amplifier power. A switched 12 V output from the radio is used to
control the power - state of the amplifier. To respond quickly to audio input and control signals, the amplifier is ON
in all vehicle power modes except OFF and CRANK Request. The internal amplifier bridges are fully powered and
unmuted when the amplifier receives the switched 12 V input.
The purpose of the amplifier is to increase the power of a voltage or current signal. The output signal of an amplifier
may consist of the same frequencies as the input signal or it may consist of only a portion of the frequencies as in the
case of a subwoofer or midrange speaker. The radio creates a low level stereo audio output signal, which is sent at
the user-defined volume level to the audio amplifier. The audio amplifier amplifies the signal and sends it to the
appropriate speakers. Each of the audio output channel circuits (+) and (-), from the amplifier have a DC bias voltage
that is approximately one half of battery voltage. The audio being played on the system is produced by a varying AC
voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker
cone to move and produce sound. The frequency (Hz) of the AC voltage signal is directly related to the frequency of
the input (audio source playing) to the audio system. Both the DC bias voltage and the AC voltage signals are needed
for the audio system to properly produce sound.
Theft Deterrent
The radio theft deterrent system is intended to disable or limit radio functionality if incorrect vehicle information is
received by the radio. The radio disables functionality if the VIN information received by the radio does not match
the VIN information that has been learned by the radio. The radio receives this information via serial data. A possible
cause of incorrect VIN info could be the radio was originally installed in another vehicle.
The radio has the following theft operating modes as part of the theft deterrent system:
• Normal Mode: The radio has learned a correct VIN sequence and the VIN information received via serial data
matches the learned VIN sequence. In this mode the radio has full functionality.
• No VIN Mode: The radio has not received or learned a correct VIN sequence. In this mode the radio has
limited functionality.
• Theft Detected Mode: The radio has learned a correct VIN sequence and the VIN information received via
serial data does NOT match the learned VIN sequence. In this mode the radio may be disabled or have limited
functionality. The radio display will indicate that theft protection is active.
Auxiliary Audio Input Jack (If equipped)
The infotainment system may have a 3.5 mm (1/8 in.) auxiliary audio input jack located in the center console. The
auxiliary audio input jack may interface directly with the radio, or be connected to the infotainment system via a
Multimedia Player Interface Module. When a portable audio playback device is connected to the auxiliary jack, an
internal switch detects the connection and the radio will switch to AUX as the audio source. Audio signals from the
device are sent to the radio from the auxiliary jack via the left, right, and common audio signal circuits.
• When a device is first connected to the 3.5 mm (1/8 in.) input jack the infotainment system automatically
switches to that device. If an auxiliary device has already been connected, press the AUX or CD/AUX button
to select the device.
• Playback of an audio device that is connected to the 3.5 mm jack can only be controlled using the controls on
the device.
• The volume control on the device may need to be adjusted to ensure sufficient playback volume through the
infotainment system.
USB Port (If Equipped)
The infotainment system may have a USB connector located in the center console. The USB connector may interface
directly with the radio, or be connected to the infotainment system via a Multimedia Player Interface Module. The
USB connector supports both USB standards 1.1 and 2.0.
USB Supported Devices:
• USB Flash Sticks (Thumb Drives)
• Portable USB Hard Drives
• Portable Digital Media Players (iPODA®, ZUNEA®, etc)
Depending on the USB device, some devices may not be recognized, or some features/functions may not be able to
be controlled with the radio controls. USB HUB devices are not supported.
BluetoothA® (If Equipped)
BluetoothA® wireless technology is a short-range communications technology intended to replace the cables
connecting portable and/or fixed devices while maintaining high levels of security. The operating range of the signal
is approximately 30 feet.
The available features and functions are determined by the type of device and the software within the devices being
used. For a feature or function to operate, it must be supported in both devices.
The first connection between devices is established through a process called pairing. In order to pair two devices, a
password (passkey) has to be exchanged between the two devices. One device will generate the password, the other
device accepts the password to complete the process. Once the devices are paired, future connections between the
devices will occur automatically when the devices are on and within range of each other.
The BluetoothA® hardware is internal to the radio. The radio supports streaming of data (music, voice, information)
from cellular phones and other mobile devices that support those features. The radio may also be capable of
interfacing with cellular phones for hands-free features.
• The device must be paired to the radio to use the available BluetoothA® feature(s). The pairing process must
only be performed once for each device, unless that device's information is deleted.
• Up to five devices can be paired to the system, but only one can be connected at any given time.
• Streaming Audio allows playing music from the mobile device wirelessly. Music stored on the mobile device
can be viewed and controlled from the display.
• To stream audio from a mobile device, the device must be unlocked, and any additional applications should be
closed.
Refer to the vehicle owners manual, supplements, and the device manufacturers information for pairing instructions.
Applications (If equipped)
When the system is equipped with BluetoothA®, the system may be capable of using applications, commonly
referred to as apps.
The term application refers to any piece of software that works on a system (hardware) that is being operated by it's
own software. Applications are typically small software programs which uses the hardware to perform a specific
task, as opposed to operating the entire system.
• For an application to be used, it must be installed on both the vehicle infotainment system and a compatible
mobile device.
• The device must be connected to the system. this may be done wirelessly via BluetoothA®, or via the vehicle
USB port. Refer to the device manufacturers information for the proper connection method.
• When the device is connected, the application on the radio is used to remotely access and control the
application on the mobile device.
• The application must work correctly on the device to work with the vehicle infotainment system.
• The user may be required to log-in to the application on the mobile device before using the application from
the vehicle controls.
• Using applications will use the device's data plan.
• The device must be unlocked, and any additional applications should be closed.
Refer to the owner's manual and supplements for information on mobile devices, control, and operation.
Navigation System Components and Features (if equipped)
The navigation system, if equipped, provides the following:
• Connection to the global positioning system (GPS) antenna, which provides the vehicle position information.
• Route guidance with verbal prompts to the operator.
• Map data for navigation and map route guidance, stored on the internal hard drive.
• Traffic and weather information for display on the navigation system map (with active subscription, where
available).
The global positioning system (GPS) antenna is part of the multi-band antenna located on the roof of the vehicle. The
GPS antenna is used to collect the signals of the orbiting GPS satellites. Within the antenna is housed a low noise
amplifier that allows for a more broad and precise reception of this data. The GPS antenna amplifier is powered
through the coaxial cable.
The antenna is connected to the navigation radio through a signal splitter. The signal splitter is a component for
dividing the navigation signal into two paths without any transmission loss. This allows the use of a single GPS
antenna to provide a signal to both the navigation radio and the telematics communication interface module.
The map will display the route to the selected destination. Voice prompts alert the operator of upcoming events
(turns) and arrivals at the destination. The navigation system will automatically recalculate if the route is not
followed. The navigation radio uses data received from the global positioning system (GPS) satellites, the vehicle
speed signal. and serial data information to accurately display the current position of the vehicle.
The map database provides point of interest information. Points of interests are locations that are frequently visited.
Points of interest can be can be displayed on the map or set as a destination. The following are some of the available
Points of interests:
• Gas Station
• Restaurant
• College
• Police Station
XM NavTraffic™ is a subscription based service that enhances the navigation system with live traffic information.
The service provides information on traffic conditions such as traffic speed, accidents, disabled vehicles,
construction and road closings.
The integrated XM satellite radio receives the information. When Traffic Information is turned ON in the
configuration menu, the available information will be displayed on the map screen.
The traffic information can vary based upon coverage in the area, and coverage is not available in all areas. No
information will be displayed if coverage is not available, if there is no traffic information for the area, or if there is
no subscription to receive the information.
A subscription fee is required in order to receive the XM NavTraffic™ service. No traffic data will be displayed
without a current subscription.
XM NavWeather™ is a subscription based service that transmits weather information to the integrated XM satellite
radio. Real time information such as current and future weather and road conditions, atmospheric conditions, and
National Weather Service warnings is provided, as well as 3 day forecasts for some cities. Received information is
available to be displayed on the Weather Info screen.
A subscription fee is required in order to receive the XM NavWeather™ service. No weather data will be displayed
without a current subscription.
OnStarA® (If equipped)
When OnStar is activated, a serial data message is sent to the radio that activates a software program. When the
software begins its process, the fade goes to the front, Bass and Treble are set to the mid range, the outputs are mono,
and the audio source is OnStar. OnStar takes priority over any other audio source. All of these actions are preset
values stored in the radio.
For additional OnStar information, refer to OnStar Description and Operation.
Steering Wheel Controls (If equipped)
Some audio functions are available using the steering wheel controls. The steering wheel controls duplicate the
function of the primary controls available on the radio.
For additional information on steering wheel controls, refer to Steering Wheel Controls Description and
Operation .
Auto Volume Control
With auto volume control, the audio system will adjust automatically to make up for road and wind noise as you
drive, by increasing the volume as vehicle speed increases. To use auto volume control, set the volume at the desired
level, and then select either Low, Medium, or High. To turn auto volume control off, select the Off screen button.
SPECIAL TOOLS AND EQUIPMENT
SPECIAL TOOLS
|
Illustration |
Tool Number/Description |
 |
EL-50334-20 |
|
Illustration |
Tool |
|
EL-50334-50 |
|
Illustration |
Tool |
|
EL-48028 |
|
Illustration |
Tool |
|
У 0^^ |
EL-49903-1 Test Antenna, Navn- |
 |
EL-49903-2 |
 |
EL-49903-3A |
 |
EL-50334-12 |
 |
EL-50334-13 |
 |
EL-50334-14 |
|
Illustration |
Tool |
|
EL-50334-15 Video Bypass Cable |
SPECIAL TOOLS (MIT TOOL INSTRUCTIONS)
Bluetooth Pairing for Vehicles with Radio RPO: UF7
Either reset the pin code on the radio to 0000, or go under Device Info on the radio and see what the pin code is (to
enter it later on the MIT).
1. Turn the BT discoverable ON in the radio Bluetooth settings.
2. Press Pair Device on radio (DO NOT PRESS SEARCH BLUETOOTH DEVICES ON THE RADIO).
3. Press the Pair button on the MIT.
4. When the three LED lights begin flashing on the MIT, enter the pin code (either 0000 if you reset it to that or
what the radio pin code was).
5. MIT will then automatically connect with the radio and should show "MIT Connected" message.
Make test call and the audio streaming test.
Holden Radio Bluetooth Pairing Instructions
1. Using the radio controls, place the radio into "Discoverable Mode".
2. Place the MIT into Bluetooth mode by pressing TEST SELECTOR until the Bluetooth LED is illuminated.
3. With the MIT in Bluetooth mode Press and Release the #1 button (the Bluetooth LED will begin to slowly
blink).
4. Now Press and release the PAIR/CALL button on the MIT (the Bluetooth LED will begin to blink a little
faster).
5. On the radio Enter the PASSKEY when prompted: (press "0000" then Press "OK").
6. The MIT and radio will PAIR and CONNECT (the Bluetooth LED will be Fast Flashing).
7. Use as regular MIT at this point.
For all other Radios
1. Verify connection of the MIT to the USB port.
2. Press and release the TEST SELECTOR button until the Bluetooth LED illuminates.
3. Disable all other Bluetooth devices present in the vehicle (ie. cell phones, laptops, etc.).
1. Use the vehicle controls to place the radio into Bluetooth Pairing mode. The vehicle will prompt you with a
security code.
2. Press and release the PAIR/CALL button. The Bluetooth LED will blink slowly while preparing to have a
security code entered.
3. Wait for the all three LEDs to blink confirming it is ready to have the security code entered.
4. Enter the code with the MIT keypad and hit ENTER.
5. The Bluetooth LED will blink slowly while pairing/bonding and move to a quick flash once paired/bonded.
The vehicle should confirm pairing/bonding is complete.
1. Confirm pairing/bonding is complete - the Bluetooth LED will be in a quick flash mode.
2. On some radios the MIT automatically begins streaming audio via A2DP. The audio playback will confirm
that the Bluetooth connection using streaming and the audio is working correctly.
3. On other radios you will need to select Bluetooth Audio from the Source menu to verify Audio Streaming.
4. Audio playback confirms that the Bluetooth connection using Streaming Audio is working correctly.
5. Placing a test call will temporarily stop the streaming audio function, but upon disconnection of that test call,
the streaming audio from the MIT will resume.
1. Confirm pairing/bonding is complete - the Bluetooth LED will be in a quick flash mode. If the vehicle is
equipped with streaming audio, and the radio is set to play a Bluetooth audio file, the streaming audio
playback will be audible.
2. Press and release PAIR/CALL button to place a test call. Streaming audio will be temporarily turned off.
3. Use the vehicle controls to answer the call.
NOTE: If the call is not answered within several rings, the MIT's audio files will not
transmit, even though an active call is occurring.
4. Audio playback confirms that the Bluetooth connectivity is working correctly.
NOTE: The MIT will remain paired/bonded when the call is ended by the vehicle. To re-
test the call function, place the MIT in Bluetooth mode and press and release
the Pair button to reconnect. When testing is completed, delete MIT from the
audio system before returning the vehicle to the customer.
5. Use the vehicle controls to end the call. If applicable, streaming audio will resume.
1. Verify connection of the MIT as stated above.
2. Press and release the TEST SELECTOR button until the MIT AUX LED illuminates.
3. Use the vehicle controls to put the audio system into Audio (Line-In) mode.
4. Audio playback confirms that the audio input is working correctly.
1. Verify connection of the MIT as stated above.
2. Press and release the TEST SELECTOR button until the MIT USB LED illuminates.
3. Use the vehicle controls to put the audio system into USB mode.
NOTE: Volume levels may vary dependent upon vehicle audio system.
4. Audio playback confirms that the USB is working correctly.
Troubleshooting Guide
If the MIT unit is still not working properly after following the below troubleshooting, the unit is malfunctioning and
should be repaired or replaced.
• Verify the MIT is powered on correctly as indicated by the green Power LED.
• If Power LED is not illuminated, verify USB power source is working properly.
• If USB power adapter is being used to power the MIT, check and, if necessary, replace the fuse in adapter.
• Verify Aux/Line-In test cable is inserted properly into the vehicle audio input jack. Verify the MIT is in
Aux/Line-In mode as indicated by the red AUX LED.
• Verify the vehicle audio system is in Auxiliary or Line-in mode. Verify the vehicle audio system volume is
turned up and not in mute mode.
• Verify MIT is in USB mode as indicated by the red USB LED. Verify the vehicle audio system is in USB
mode.
• Verify the vehicle audio system volume is turned up and not in mute mode.
• Delete previous devices stored in the device list of the radio and the pair the MIT
• Remove USB cable, and then reconnect to reset the MIT. Carefully follow the bonding instructions for the
correct Passkey procedure.
• Verify the MIT is paired with the vehicle. This is indicated by the quick flashing Bluetooth LED.
• Audio system should have indicated the MIT is bonded.
Article GUID: A00884689
ACCESSORIES & EQUIPMENT
Cruise Control - Volt
SPECIFICATIONS
FASTENER SPECIFICATIONS
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Reusable Threaded Fastener Tightening Specifications_______________ | |||||||
| |||||||
SCHEMATIC WIRING DIAGRAMS
CRUISE CONTROL WIRING SCHEMATICS
Fig. 1: Cruise Control
Courtesy of GENERAL MOTORS COMPANY
DIAGNOSTIC INFORMATION AND PROCEDURES
DTC P0571: CRUISE CONTROL BRAKE SWITCH CIRCUIT
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Cruise Control Brake Switch Circuit
Circuit/System Description
The engine control module (ECM) monitors the brake pedal position sensor. When the brake pedal is applied,
the ECM detects a predetermined voltage signal. The ECM sends a serial data message to the body control
module (BCM) indicating the status of the stop lamps.
This diagnostic test functions on the assumption that a sudden decrease in vehicle speed is caused by a brake
pedal application. When the ECM detects that there is a 4.2 km/h (2.6 mph) or greater decrease in vehicle speed
within 0.25 s without a transition of the stop lamp switch, the ECM sets DTC P0571.
Conditions for Running the DTC
• The engine speed is greater than 700 RPM.
• The traction control system or the antilock brake system are not active and have not malfunctioned.
• The vehicle speed is greater than 48 km/h (30 mph).
• The diagnostic will disable when the wheel speed is less than 16 km/h (10 mph).
Conditions for Setting the DTC
The BCM detects either a low voltage signal on the stop lamp switch signal circuit when the serial data message
from the ECM indicates the brakes are applied, or a high voltage signal on the stop lamp switch signal circuit
when the serial data message from the ECM indicates the brakes are not applied.
Actions Taken When the DTC Sets
• The cruise control system is disabled.
• The malfunction indicator lamp (MIL) will not illuminate.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear after 40 malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify that the stop lamps operate properly and that no B22 Brake Pedal Position Sensor related DTCs are
set.
• If brake pedal position sensor related DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle
• If no brake pedal position sensor related DTCs are set
2. Verify that no DTCs are set, except DTC P0571.
• If any other DTC is set, except DTC P0571
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
• If only DTC P0571 is set
3. Replace the K20 Engine Control Module.
4. Verify DTC P0571 does not set when operating the vehicle within the conditions for running the DTC.
Replace the K9 Body Control Module.
5. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for BCM or ECM replacement, programming and setup.
DTC P0572 OR P0573: BRAKE SWITCH CIRCUIT 1 LOW/HIGH VOLTAGE
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
Brake Switch Circuit 1 Low Voltage
DTC P0573
Brake Switch Circuit 1 High Voltage
|
Diagnostic Fault Information | ||||||||||
| ||||||||||
|
Circuit/System Description |
The brake pedal position sensor signal circuit is a B+ input from the body control module (BCM) to the engine
control module (ECM). The BCM and ECM monitor the brake pedal position sensor signal circuit to detect
when the brake pedal has been applied. When the brake pedal is applied, the BCM supplies B+ on the stop lamp
signal circuit and also sends a serial data message to the ECM indicating that the brake pedal has been applied.
Conditions for Running the DTC
• The engine is running.
• Battery voltage is greater than 11.5 V.
• Brakes applied.
Conditions for Setting the DTC
This DTC will set when the ECM detects a short to ground or an open on the discrete brake signal circuit when
the serial data message from the BCM indicates the brakes are applied. This diagnostic will run when the serial
data message and the voltage signal on the brake switch signal circuit do not match for 8 out 10 times, and the
condition is present for greater than 2 s.
This DTC will set when the ECM detects a short to voltage on the discrete brake signal circuit when the serial
data message from the BCM indicates the brakes are not applied. This diagnostic will run when the serial data
message and the voltage signal on the brake switch signal circuit do not match for 8 out 10 times, and the
condition is present for greater than 2 s.
Actions Taken When the DTC Sets
• The malfunction indicator lamp (MIL) will not illuminate.
• The cruise control system is disabled.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear after 40 malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Ignition On/Vehicle in Service Mode.
2. Verify that the stop lamps operate properly and that no B22 Brake Pedal Position Sensor related DTCs are
set.
• If brake pedal position sensor related DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle
• If no brake pedal position sensor related DTCs are set
3. Refer to Circuit/System Testing.
Circuit/System Testing
NOTE: All components may need to be disconnected on the cruise control brake signal
circuit to isolate a short to voltage, short to ground or an open/high resistance
condition. Use the schematic to identify the proper brake signal terminal (circuit
6311) at the K20 Engine Control Module.
1. Ignition/Vehicle Off, disconnect the harness connector at the K20 Engine Control Module, Ignition
On/Vehicle in Service Mode.
2. Connect a test lamp between the signal circuit terminal and ground.
3. Verify the test lamp turns ON and OFF when pressing and releasing the brake pedal.
• If the test lamp is always OFF
1. Ignition/Vehicle Off, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If not infinite resistance, repair the short to ground on the circuit.
• If infinite resistance.
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K9 Body Control Module.
• If the test lamp is always ON
1. Ignition/Vehicle Off, disconnect the harness connector at the K9 Body Control Module, Ignition
On/Vehicle in Service Mode.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the source of voltage on the circuit.
• If less than 1 V replace the K9 Body Control Module.
• If the test lamp turns ON and OFF
4. Replace the K20 Engine Control Module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for control module replacement, programming, and setup.
DTC P0575: CRUISE CONTROL SWITCH SIGNAL MESSAGE COUNTER INCORRECT
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Cruise Control Switch Signal Message Counter Incorrect
Circuit/System Description
When a cruise control function switch is activated, the body control module (BCM) detects a predetermined
voltage. The BCM sends a serial data message to the engine control module (ECM) indicating the function that
has been requested.
Conditions for Running the DTC
• The ignition is ON.
• The vehicle speed is greater than 40 km/h (25 MPH) and the cruise control is engaged.
Conditions for Setting the DTC
• The ECM receives an invalid cruise control switch status serial data message from the BCM.
• This diagnostic runs continuously.
Actions Taken When the DTC Sets
DTC P0575 is a type C DTC.
Conditions for Clearing the DTC
DTC P0575 is a type C DTC.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
DTC Type Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify that no DTCs are set, except DTC P0575.
• If any other DTC is set, except DTC P0575
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
• If only DTC P0575 is set
2. Replace the K9 Body Control Module.
3. Verify DTC P0575 does not set when operating the vehicle within the Conditions for Running the DTC.
Replace the K20 Engine Control Module.
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for BCM or ECM replacement, programming, and setup.
DTC P0703: BRAKE SWITCH SIGNAL MESSAGE COUNTER INCORRECT
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Brake Switch Signal Message Counter Incorrect
Circuit/System Description
The body control module (BCM) monitors the brake pedal position sensor. When the brake pedal is applied, the
BCM detects a predetermined voltage signal. The BCM sends a serial data message to the engine control
module (ECM) indicating the status of the stop lamps.
Conditions for Running the DTC
The engine is ON.
Conditions for Setting the DTC
• The ECM receives an invalid brake pedal status serial data message from the BCM.
• This diagnostic runs continuously.
Actions Taken When the DTC Sets
• The malfunction indicator lamp (MIL) will not illuminate.
• The cruise control system is disabled.
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear after 40 malfunction-free ignition cycles have occurred.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify that no DTCs are set, except DTC P0703.
• If any other DTC is set, except DTC P0703
2. Replace the K9 Body Control Module.
3. Verify DTC P0703 does not set when operating the vehicle within the conditions for running the DTC.
Replace the K20 Engine Control Module.
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for BCM or ECM replacement, programming, and setup.
DTC P158A: CRUISE CONTROL CALIBRATION INCORRECT
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptor
Cruise Control Calibration Incorrect
Circuit/System Description
The type of cruise control system the vehicle has is programmed into the body control module and the engine
control module. If this information is not the same in both modules DTC P158A will set.
Conditions for Running the DTC
This diagnostic runs continuously.
Conditions for Setting the DTC
The type of cruise control system programmed into the body control module does not match what is
programmed into the engine control module.
Actions Taken When the DTC Sets
DTC P158A is a Type C DTC.
Conditions for Clearing the DTC
DTC P158A is a Type C DTC.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
DTC Type Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify that no DTCs are set, except DTC P158A.
• If any other DTC is set, except DTC P158A
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
• If only DTC P158A is set
2. Reprogram the K9 Body Control Module and the K20 Engine Control Module one after the other. Do not
place the Ignition On/Vehicle in Service Mode between each programming event.
3. Verify DTC P158A does not set when operating the vehicle within the conditions for running the DTC.
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for control module replacement, programming, and setup.
SYMPTOMS - CRUISE CONTROL
NOTE: The following steps must be completed before using the symptom tables.
1. Before using the symptom diagnostic table, perform the Diagnostic System Check - Vehicle in order to
verify the following conditions:
• There are no DTCs set.
• The module can communicate via the serial data.
2. Review the system operation in order to understand the system functions. Refer to Cruise Control
Description and Operation.
Visual/Physical Inspection
• Inspect for aftermarket devices which can affect the operation of the Cruise Control System. Refer to
Checking Aftermarket Accessories .
• Inspect the accessible system components or the visible system components for obvious damage or for
obvious conditions which can cause the symptom.
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for
Intermittent Conditions and Poor Connections .
Symptom List
Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:
Cruise Control Malfunction - DTC B3794, P0564, P0565, P0567, P0568, P056C, P0580, P0581,
P155A-P155C, or P162C
Cruise Control Indicator Malfunction
CRUISE CONTROL INDICATOR MALFUNCTION
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
Circuit/System Description
The instrument cluster illuminates the cruise control engaged indicator based on serial data messages received
from the engine control module (ECM). The indicator is commanded ON when the cruise control system is
controlling vehicle speed, and turned OFF with the system disengaged.
Reference Information
Schematic Reference
Cruise Control Schematics
Connector End View Reference
COMPONENT CONNECTOR END VIEWS - INDEX
Description and Operation
Cruise Control Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Verify the cruise control indicator turns ON and OFF when commanding the All Indicators ON and OFF
with a scan tool.
• If the indicator does not turn ON and OFF
Replace the P16 Instrument Cluster.
• If the indicator turns ON and OFF
2. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for instrument cluster replacement, programming and setup.
CRUISE CONTROL MALFUNCTION - DTC B3794, P0564, P0565, P0567, P0568, P056C, P0580,
P0581, P155A-P155C, OR P162C
Diagnostic Instructions
• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Refer to Diagnostic Procedure Instructions to provide an overview of each diagnostic category.
DTC Descriptors
DTC B3794
Cruise Control Function Request Circuit
Cruise Control Multifunction Switch Circuit
Cruise Control Switch Circuit
Cruise Control Resume Switch Circuit
Cruise Control Set Switch Circuit
Cruise Control Cancel Switch Circuit
Cruise Control Multifunction Switch Circuit Low Voltage
Cruise Control Multifunction Switch Circuit High Voltage
Cruise Control Switch State Undetermined
Cruise Control Set/Coast Switch 2 Circuit
Cruise Control Resume/Acceleration Switch 2 Circuit
Vehicle Speed Limiting/Warning Switch Circuit
For symptom byte information, refer to Symptom Byte List .
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Diagnostic Fault Information | ||||||||||
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Circuit/System Description | |||||||||||||||
The cruise control switch is an input to the body control module (BCM). The BCM monitors the cruise control
on/off, set/coast, resume/accelerate and cancel switches via the cruise control switch signal circuit in order to
detect when the driver has requested to perform a cruise control function. The BCM detects a specific voltage
signal on the cruise control switch signal circuit when a switch is applied. The engine control module (ECM)
receives the requested cruise control switch function from the BCM via a serial data message.
Conditions for Running the DTC
• The cruise control switch is ON.
• Ignition On/Vehicle in Service Mode
Conditions for Setting the DTC
The BCM detects an invalid voltage signal on the cruise control switch signal circuit for 1 s.
Stuck switch for either Resume/Accel or Set/Coast button for 60 s.
• The BCM detects an invalid voltage signal on the cruise control switch signal circuit for greater than 2 s
and sends a serial data message to the ECM. The ECM sets these DTCs when the message is received.
• The ECM runs this diagnostic continuously.
• The ECM detects an invalid voltage signal on the cruise control switch signal circuit.
• The above condition is present for greater than 2 s.
• The ECM runs this diagnostic continuously.
The ECM is unable to determine the state of the cruise control switch.
The ECM is unable to determine the state of the vehicle speed limiting switch.
Actions Taken When the DTC Sets
• The malfunction indicator lamp (MIL) will not illuminate.
• The cruise control system is disabled.
DTCs P0564, P0565, P0567, P0568, P056C, P0580, P0581, P155A and P162C are type C DTCs
Conditions for Clearing the DTC
• The condition responsible for setting the DTC no longer exists.
• A history DTC will clear after 40 malfunction-free ignition cycles have occurred.
DTCs P0564, P0565, P0567, P0568, P056C, P0580, P0581, P155A and P162C are type C DTCs.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Circuit Testing
Connector Repairs
Testing for Intermittent Conditions and Poor Connections
Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Ignition On/Vehicle in Service Mode.
2. Verify that the stop lamps operate properly and that no B22 Brake Pedal Position Sensor related DTCs are
set.
• If brake pedal position sensor related DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle
• If no brake pedal position sensor related DTCs are set
3. Verify the scan tool K9 Body Control Module Cruise Control Switch Status parameter changes between
Off and On, Resume and Set when switching between each position on the cruise control switch.
• If the parameter does not change
Refer to Circuit/System Testing.
• If the parameter changes
4. Verify that no conditions that may inhibit cruise control operation are present. Refer to the K20 Engine
Control Module scan tool data list Cruise Control Inhibit Reason parameter. Refer to the Cruise Control
Description and Operation for a list of inhibit reasons.
• If the cruise control system has a reason why it is inhibited
Repair the condition that is causing the inhibit reason.
• If the cruise control system does not have any reasons why it may be inhibited
5. Verify that no cruise control related DTCs are set.
• If any cruise control related DTCs are set
Refer to Circuit/System Testing.
• If no cruise control related DTCs are set
6. All OK.
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Circuit/System Testing | ||
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1. Ignition/Vehicle Off, disconnect the harness connector at the S70L Steering Wheel Controls Switch-Left,
Ignition On/Vehicle in Service Mode.
2. Verify a test lamp illuminates between the ignition circuit and ground.
• If the test lamp does not illuminate
1. Ignition/Vehicle Off, disconnect the harness connector at the K9 Body Control Module.
2. Test for greater than 100 Q between the ignition circuit and ground.
• If 100 Q or less, repair the short to ground on the circuit.
• If greater than 100 Q
3. Test for less than 2 Q in the ignition circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, test or replace the K9 Body Control Module.
• If the test lamp illuminates
3. Verify the scan tool K9 Body Control Module Cruise Control Switch Status parameter is Open/Short to
Ground or Undetermined State.
• If not Open/Short to Ground or Undetermined State
1. Ignition/Vehicle Off, disconnect the harness connector at the K9 Body Control Module,
Ignition/Vehicle On.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 Body Control Module.
• If Open/Short to Ground or Undetermined State
4. Install a 3 A fused jumper wire between the signal circuit and the ignition circuit.
5. Verify the scan tool K9 Body Control Module Cruise Control Switch Status parameter is Short to Battery
or Undetermined State.
• If not Short to Battery or Undetermined State
1. Ignition/Vehicle Off, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 Q in the signal circuit end to end.
• If 2 Q or greater, repair the open/high resistance in the circuit.
• If less than 2 Q, replace the K9 Body Control Module.
• If Short to Battery or Undetermined State
6. Test or replace the S70L Steering Wheel Controls Switch-Left.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Refer to Control Module References for control module replacement, programming and setup.
REPAIR INSTRUCTIONS
CRUISE CONTROL SWITCH REPLACEMENT
Fig. 2: Cruise Control Switch
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Courtesy of GENERAL MOTORS COMPANY | ||||||||
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DESCRIPTION AND OPERATION
CRUISE CONTROL DESCRIPTION AND OPERATION
Switch - |
Wheel
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Callout |
Component Name |
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K20 |
K20 Engine Control Module |
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S70L |
S70L Steering Wheel Controls Switch - Left |
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P16 |
P16 Instrument Cluster |
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K9 |
K9 Body Control Module |
Cruise control is a speed control system that maintains a desired vehicle speed under normal driving conditions
at speeds above 40 km/h (25 mph). Steep grades may cause variations in the selected vehicle speeds.
The following are the main components of the Cruise Control System:
• The accelerator pedal
• The brake pedal position (BPP) sensor
• The body control module (BCM)
• The cruise on/off switch
• The cruise control cancel switch
• The + RES switch (equivalent to resume/accelerate switch)
• The - SET switch (equivalent to set/coast switch)
• The engine control module (ECM)
• The throttle actuator control (TAC) motor (gasoline engines only)
• The vehicle speed sensor
The body control module (BCM) monitors the signal circuit of the cruise control switches, which are located on
the steering wheel. The BCM relays the cruise control switch status to the engine control module (ECM) via the
serial data circuit. The ECM uses the status of the cruise control switch to determine when to capture and
maintain the vehicle speed. The ECM monitors the vehicle speed signal circuit in order to determine the desired
vehicle speed.
Voltage is supplied to the cruise control switch via the steering wheel control switch reference voltage circuit
supplied by the BCM. The cruise control function switches are arranged in a resistive ladder design, with each
cruise control function switch having a different resistance value. The BCM detects a specific voltage value that
is associated with the cruise control function switch being activated. The BCM sends a serial data message to
the ECM indicating that the on/off switch is active. Similarly, when the normally open + RES switch or the
normally open - SET switch are pressed, the switch closes and the BCM detects the predetermined voltage
signal on the cruise control resume/accel and set/coast switch signal circuit. The BCM sends a serial data
message to the ECM indicating that the + RES switch or the - SET switch is active.
Cruise Control Engaged
The Cruise Control System will engage and adjust vehicle speeds, based on the activation of the following
cruise control switches, which are located on the steering wheel:
• On/Off
• + RES
• - SET
To engage the Cruise Control System, ensure that the vehicle speed is above 40.2 km/h (25 mph), turn the cruise
On/Off switch ON and momentarily press the - SET switch. The ECM will engage the Cruise Control System
and record the vehicle speed. The ECM sends a serial data message to the instrument panel cluster (IPC) in
order to illuminate the Cruise Engaged indicator in the IPC. Refer to the vehicle owner's manual for the location
and operation of the cruise control On/Off indicators and driver information center (DIC) messages.
Pressing the accelerator pedal while the Cruise Control System is engaged, allows the driver to override the
Cruise Control System in order to accelerate the vehicle beyond the current set vehicle speed. When the
accelerator pedal is released, the vehicle will decelerate and resume the current set vehicle speed.
The driver can also override the current set vehicle speed via the - SET switch and the + RES switch. When the
Cruise Control System is engaged, pressing and holding the - SET switch will allow the vehicle to decelerate
from the current set vehicle speed without deactivating the Cruise Control System. When the - SET switch is
released, the ECM will record the vehicle speed and maintain the vehicle speed as the new set vehicle speed.
When the Cruise Control System is engaged, momentarily pressing the - SET switch will allow the vehicle to
decelerate at a vehicle specific calibratable increment, commonly 1 km/h or 1 mph, each time that the - SET is
momentarily pressed, with a minimum vehicle speed of 38 km/h (24 mph). Refer to the vehicle Owner's Manual
for more information.
Pressing and holding the + RES switch, when the Cruise Control System is engaged, will allow the vehicle to
accelerate to a greater vehicle speed than the current set vehicle speed. When the + RES switch is released, the
ECM will record the vehicle speed and maintain the vehicle speed as the new set vehicle speed. When the
Cruise Control System is engaged, momentarily pressing the + RES switch will allow the vehicle to accelerate
at a vehicle specific calibratable increment, commonly 1 km/h or 1 mph, each time that the + RES switch is
momentarily pressed. Momentarily activating the + RES switch will recall the previous vehicle speed, after the
cruise control system has been disengaged by pressing the brake pedal, or CANCEL switch. Refer to the vehicle
Owner's Manual for more information.
Cruise Control Disengaged
The engine control module (ECM) disengages the cruise control operation based on the signals from the
following switches:
• The brake pedal position (BPP) sensor
• The On/Off switch
• The cruise control cancel switch
The Cruise Control System will disengage when the brake pedal is applied. The body control module (BCM)
monitors the BPP sensor via the BPP sensor signal circuit as the voltage signal increases while the pedal is
further applied. The ECM monitors the BPP signal through a discrete input and a serial data message signal
from the BCM indicating the brake status. When either signal indicates the brake pedal is applied, the ECM will
disengage the cruise control system.
The Cruise Control System will also disengage when the cruise control on/off switch is switched OFF, or the
cruise control cancel switch is activated. The body control module (BCM) determines when the cruise control
cancel switch is activated. When the normally open cancel switch is closed, the BCM detects the predetermined
voltage signal on the cruise control function switch circuit. The vehicle speed stored in the memory of the
engine control module will be erased when the cruise control On/Off switch is turned OFF, or the ignition
switch is turned OFF. The BCM sends a serial data message to the ECM in order to disengage the cruise control
system. When the Cruise Control System has been disengaged, the ECM sends a serial message to the
instrument panel cluster (IPC) in order to turn OFF the Cruise Engaged indicator.
Every time the Cruise Control System is disengaged, the ECM will keep track of the reason for system
disengagement. The last 8 disengagement reasons will be recorded within the ECM memory. The scan tool will
display the last 8 Cruise Disengage History parameters, in which one out of approximately 50 possible reasons
will be displayed in each of these 8 parameters. For the disengagement reason to be displayed within the scan
tool parameter the Cruise Control System is active and disengagement is requested.
When engagement of the system is requested but an engagement inhibit is present, the most recent inhibit
reason is recorded in the ECM history. The scan tool will display the most recent inhibit reason, in which one
out of approximately 50 possible reasons will be displayed.
Cruise Control Inhibited
The engine control module (ECM) inhibits the cruise control operation when any of the following conditions
exist:
• The ECM has not detected a brake pedal activation from the body control module (BCM) this ignition
cycle.
• A Cruise Control System DTC has been set.
• The vehicle speed is less than 38.6 km/h (24 mph).
• The vehicle speed is too high.
• The vehicle is in PARK, REVERSE, NEUTRAL, or 1st gear.
• The engine RPM is low.
• The engine RPM is high.
• The system voltage is not between 9 volts and 16 volts.
• The Antilock Brake System (ABS)/Traction Control System (TCS) is active for more than a calibratable
time (typically 0.3 to 0.7 seconds).
Cruise Control Inhibit Reasons
This is a general list of inhibit reasons. Not every inhibit reason is applicable to all vehicles. Refer to the scan
tool inhibit reason list for the last 8 reasons that have been recorded during the current ignition cycle.
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Scan Tool Name |
Description |
Long Description |
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Acceleration Rate too High |
High acceleration |
The vehicle acceleration rate is too |
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Acceleration Time |
Rate limiting fault |
Cruise torque request rate limiting |
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Adaptive Cruise Control |
Adaptive cruise control option |
The cruise control type (adaptive |
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Antilock Braking System |
Antilock Braking System Active |
The antilock braking system was |
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Automatic Braking Engine |
Automatic braking engine torque |
An engine control module to electronic |
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Automatic Braking Malfunction |
Brake system malfunction |
The electronic brake control module |
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Axle Torque Serial |
Axle Torque Serial |
The adaptive cruise control is being |
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Battery Voltage Too High |
Voltage above high voltage |
The ignition voltage is too high at the |
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Battery Voltage Too Low |
Voltage below low voltage |
The ignition voltage is low at the |
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Brake Pedal Applied |
Brake pedal apply |
The brake pedal was applied. |
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Scan Tool Name |
Description |
Long Description |
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Brake Pedal Not Initialized |
Brake before cruise |
The brake pedal has not been seen as |
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Brake Pedal Position |
Brake pedal position signal |
A brake pedal apply circuit fault has |
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Brake Pedal Position Signal |
DTC P0703 is active or |
A serial data fault is active or |
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Brake Pedal Pressure Detected |
Brake pedal driver applied |
A brake pedal apply has been detected |
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Brake Pedal Released Position |
Brake apply sensor home |
The brake pedal position sensor |
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Brake System Malfunction |
Adaptive cruise control |
Adaptive cruise control automatic |
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Calculated Torque |
Calculated engine torque |
The engine torque calculation is |
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Clutch Pedal Applied |
Clutch switch active |
The clutch pedal was applied. |
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Coast Below Minimum Speed |
Coast below low speed inhibit |
The Set/Coast switch was depressed |
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Coast Mode |
Coast disengage |
Cruise control is in coast mode with |
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Control Function Active |
DLC override |
A scan tool is plugged into the Data |
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Control Module Memory |
Memory failure |
A control module memory failure has |
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Control Module Processor |
Processor integrity fault (random |
An engine control module software |
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Crawl Mode Active |
Crawl Mode Active |
Crawl mode is active and inhibiting |
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Cruise Control Cancel Switch |
Cancel switch active |
The cruise control cancel switch was |
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Scan Tool Name |
Description |
Long Description |
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Cruise Control Software |
Sequence of completion checks |
A cruise control software execution |
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Cruise Control Switch Inactive |
On/Off switch in Off state |
The cruise control On/Off switch is |
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Cruise Control Switch Invalid |
Analog cruise switch input out of |
The cruise control switch voltage |
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Cruise Control Switch Serial |
Serial data fault (cruise switch |
The cruise control switch serial data |
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Deceleration Rate Too High |
High deceleration |
The vehicle deceleration rate is too |
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Diagnostic Trouble Code |
Malfunction in PCM/ECM (DTC |
A DTC is active or in history that |
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Distance Sensing Cruise |
Distance Sensing Cruise Control |
Adaptive cruise control is being |
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Distance Sensing Cruise |
Distance Sensing Cruise Control |
Adaptive cruise control is being |
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Distance Sensing Cruise |
Serial data fault for adaptive |
A distance sensing cruise control |
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Distance Sensing Cruise |
Distance sensing cruise control |
The distance sensing cruise control |
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Distance Sensing Cruise |
Distance Sensing Cruise Control |
Adaptive cruise control is being |
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Distance Sensing Cruise |
Distance Sensing Cruise Control |
Adaptive cruise control is being |
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Distance Sensing Cruise |
Distance Sensing Cruise Control |
Adaptive cruise control is being |
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Driven Wheel Speed Higher |
Driven wheel speed greater |
The driven wheel speed is greater than |
|
Engine Control Module |
PCM/ECM inhibit (RAM |
Engine control module internal |
|
Scan Tool Name |
Description |
Long Description |
|
Engine Control Module (ECM) |
ECM running reset |
An engine control module running |
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Engine Overspeed Protection |
Injectors disabled (engine |
Engine RPM limiter active with fuel |
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Engine Overtemperature |
Engine metal overtemp active |
The engine is over temperature. The |
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Engine Run Time |
Engine run time not elapsed |
The engine has not been running long |
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Engine Speed |
Engine speed too low or too high |
The engine RPM is too low (near stall) |
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Excessive Accelerator Position |
Pedal greater than cruise |
The driver has overridden cruise |
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1st Gear |
First Gear |
Transmission is engaged in 1st gear. |
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Gear Change without Applied |
Manual transmission out of gear |
Manual transmission shifted to Neutral |
|
Hill Descent Control Active |
Hill Descent Control System |
The hill descent control system has |
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Hill Descent Control Serial |
Hill Descent Control Serial |
An electronic brake control module |
|
Hybrid/EV System |
Hybrid Cruise Disengage |
Cruise control is inhibited on hybrid |
|
Illegal Mode |
Illegal cruise mode |
The cruise control mode is incorrect |
|
Lane Center Control Serial |
Lane Center Control Serial |
Adaptive cruise control is being |
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Non Driven Wheel Speed |
Non-driven wheel speed greater |
The non driven wheel speed is greater |
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None |
None |
This disengagement reason may be |
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Park Brake Applied |
Park brake switch signal active |
The parking brake is applied. |
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Power Take-Off Active |
Power Take Off active |
The Power Take Off (PTO) system is |
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Rear Axle in Low Range |
Rear axle in low |
The rear axle is in low range. |
|
Scan Tool Name |
Description |
Long Description |
|
Set/Coast and Resume/Accelerate Switches Active Simultaneously |
SET and RESUME switches |
The Set/Coast and Resume/Accelerate |
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Set/Coast Switch Active With |
Over schedule tap-down |
The Set/Coast switch is selected, |
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Speed Limiting/Warning System On |
Speed limiter/warning On/Off |
Driver has turned on the Speed |
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Throttle Actuator Control |
Electronic throttle control |
The electronic throttle control system |
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Traction Control Active |
Traction control active |
The traction control system was active. |
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Traction Control System |
Traction Control System |
A fault is present in the traction control |
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Traction Control System Off |
Traction Control System Off |
The traction control system has been |
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Transfer Case in 4WD Low |
Transfer case in 4WD Low |
The transfer case is in low range. |
|
Transmission Gear Ratio |
Transmission gear fault |
A transmission DTC is active or in |
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Transmission Not in Forward |
Transmission in neutral, reverse |
The transmission gear selector is not in |
|
Vehicle Overspeed Protection |
MPH limited fuel (vehicle |
The vehicle overspeed protection is |
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Vehicle Speed Higher Than Set |
Over schedule |
Vehicle speed has exceeded driver |
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Vehicle Speed Lower Than Set |
Under schedule |
The vehicle speed is below cruise |
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Vehicle Speed Too High |
Vehicle speed exceeds high |
Vehicle speed has exceeded maximum |
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Vehicle Speed Too Low |
Vehicle speed drops below low |
Vehicle speed dropped below the |
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Scan Tool Name |
Description |
Long Description |
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torque may contribute to this | ||
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Vehicle Stability System Active |
Vehicle stability control active |
The vehicle stability control system |
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Vehicle Stability System |
Vehicle Stability System |
A fault has been detected in the vehicle |
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Vehicle Stability System Off |
Vehicle Stability System Off |
The vehicle stability control system |
Article GUID: A00884711
ACCESSORIES & EQUIPMENT
DESCRIPTION AND OPERATION
The body control system consists of the body control module (BCM), communications, and various input and
outputs. Some inputs, outputs and messages require other modules to interact with the BCM. The BCM also has
discrete input and output terminals to control the vehicle's body functions. The BCM is wired to the high speed
GMLAN serial data bus, low speed GMLAN serial data bus and Multiple LIN buses and acts as a gateway
between them.
Power Mode Master
This vehicle body control module (BCM) functions as the power mode master (PMM). The ignition switch is a
low current switch with multiple discrete ignition switch signals to the PMM for determining the power mode
that will be sent over the serial data circuits to the other modules that need this information; the PMM will
activate relays and other direct outputs of the PMM as needed. Refer to Power Mode Description and
Operation for a complete description of power mode functions.
Gateway
The body control module (BCM) in this vehicle functions as a gateway or translator. The purpose of the
gateway is to translate serial data messages between the GMLAN high speed bus and the GMLAN low speed
bus for communication between the various modules. The gateway will interact with each network according to
that network's transmission protocol.
All communication between the BCM and a scan tool is on the high speed GMLAN serial data circuits. A lost
communication DTC typically is set in modules other than the module with a communication failure.
Body Control
The various body control module (BCM) input and output circuits are illustrated in the corresponding functional
areas on the BCM electrical schematics. Refer to the Body Control System Schematics for more detailed
information.
DATA LINK COMMUNICATIONS DESCRIPTION AND OPERATION
NOTE: This is an overview of different serial data buses used by GM control modules
to communicate with each others. Use schematics to find out which serial data
buses are configured for a specific vehicle.
Circuit Description
There are many components in a vehicle that rely on information from other sources, transmit information to
other sources, or both. Serial data communication networks provide a reliable, cost effective, way for various
components of the vehicle to "talk" to one another and share information.
GM uses a number of different communication buses to insure the timely and efficient exchange of information
between control modules. When compared to each other, some of these buses are different in nature as far as
speed, signal characteristics, and behavior. An example of this is the High Speed GMLAN and Low Speed
GMLAN buses.
On the other hand, when other buses are compared to each other they have similar characteristics and simply
operate in parallel. In this case they are used to group together components which have high interaction.
Examples are the High Speed GMLAN, Powertrain Expansion, and Chassis Expansion buses. This allows them
to communicate with each other on a bus with reduced message congestion insuring faster and the more timely
exchange of information than if all vehicle control modules were on a single bus.
The majority of information that exists within a given network generally stays local; however some information
will have to be shared on other networks. Control modules designated as Gateway's perform the function of
transferring information between the various buses. A Gateway module is connected to at least 2 buses and will
interact with each network according to its message strategy and transmission models.
GMLAN provides the capability for a receiving control module to monitor message transmissions from other
control modules in order to determine if messages of interest are not being received. The primary purpose is to
allow reasonable default values to be substituted for the information no longer being received. Additionally, a
control module may set a Diagnostic Trouble Code to indicate that the control module it is expecting
information from is no longer communicating.
High Speed GMLAN Circuit Description
A High Speed GMLAN Bus is used where data needs to be exchanged at a high enough rate to minimize the
delay between the occurrence of a change in sensor value and the reception of this information by a control
device using the information to adjust vehicle system performance.
The High Speed GMLAN serial data network consists of two twisted wires. One signal circuit is identified as
GMLAN-High and the other signal circuit is identified as GMLAN-Low. At each end of the data bus there is a
120 Q termination resistor between the GMLAN-High and GMLAN-Low circuits.
Data symbols (1's and 0's) are transmitted sequentially at a rate of 500 Kbit/s. The data to be transmitted over
the bus is represented by the voltage difference between the GMLAN-High signal voltage and the GMLAN-
Low signal voltage.
When the two wire bus is at rest the GMLAN-High and GMLAN-Low signal circuits are not being driven and
this represents a logic "1". In this state both signal circuits are at the same voltage of 2.5 V. The differential
voltage is approximately 0 V.
When a logic "0" is to be transmitted, the GMLAN-High signal circuit is driven higher to about 3.5 V and the
GMLAN-Low circuit is driven lower to about 1.5 V. The differential voltage becomes approximately 2.0 (+/-
0.5) V.
Chassis High Speed GMLAN Circuit Description
The GMLAN Chassis Expansion Bus is basically a copy of the High Speed GMLAN Bus except that its use is
reserved for chassis components. This implementation splits message congestion between two parallel buses
helping to insure timely message transmission and reception. Sometimes communication is required between
the Chassis Expansion Bus and the primary High Speed GMLAN Bus. This is accomplished by using the K17
Electronic Brake Control Module (EBCM) as the Gateway module. Since the High Speed GMLAN Chassis
Expansion Bus and primary High Speed GMLAN Bus operate in the same manner, the diagnostics for each are
similar.
Powertrain High Speed GMLAN Circuit Description
The GMLAN Powertrain Expansion Bus is basically a copy of the High Speed GMLAN Bus except that its use
is reserved for Hybrid powertrain components or Diesel powertrain components in some cases. The bus is
optional based upon feature content. Sometimes communication is required between the Powertrain Expansion
Bus and the primary High Speed GMLAN Bus. This is accomplished by using the K20 Engine Control Module
(ECM) as the Gateway module. Since the High Speed GMLAN Powertrain Expansion Bus and the primary
High Speed GMLAN Bus operate in the same manner, the diagnostics for each are similar.
All diagnostic information is available only through the primary high speed GMLAN bus.
High Voltage Energy Management High Speed GMLAN Circuit Description
The GMLAN High Voltage Energy Management Bus is basically a copy of the High Speed GMLAN Bus
except that its use is reserved for Hybrid charging components of an electric vehicle. Sometimes
communication is required between the Low Speed GMLAN Bus and the High Voltage Energy Management
Bus. This is accomplished by using the K114B Hybrid Powertrain Control Module 2 as the Gateway module.
Since the High Speed GMLAN High Voltage Energy Management Bus and primary High Speed GMLAN Bus
operate in the same manner, the diagnostics for each are similar.
All diagnostic information is available only through the primary high speed GMLAN bus.
Object High Speed GMLAN Circuit Description
The GMLAN Object Bus is basically a copy of the High Speed GMLAN Bus except that its use is reserved for
the enhanced safety system. This implementation is used to isolate the heavy communication among the
enhanced safety system devices from the other vehicle buses, reducing congestion. The K124 Active Safety
Control Module is connected to the Object Bus as well as the Primary High Speed GMLAN Bus, the Chassis
Expansion Bus, and the Low Speed GMLAN Bus. The K124 Active Safety Control Module acts as a Gateway
module for all required communication between the Object Bus devices and devices on these other vehicle
buses. The GMLAN Object Bus operates in the same manner as the Chassis Expansion and Primary High Speed
buses and so the diagnostics are similar. The Object Bus is physically partitioned into a Front Object Bus and a
Rear Object Bus with each partition having its own communication enable circuit to activate the partition, but
functional operation of both is identical. The Front Object Bus standard devices are the K124 Active Safety
Control Module, the K109 Frontview Camera Module, and the B233B Radar Sensor Module - Long Range. The
Front Object Bus optional devices are the B233LF Radar Sensor Module - Short Range Left Front and the
B233RF Radar Sensor Module - Short Range Right Front. The Rear Object Bus is optional and when present
will have the K124 Active Safety Control Module and B233R Radar Sensor Module - Short Range Rear on the
bus, and optionally the Radar Sensor Module - Short Range Right Rear. All Object Bus components are
powered by the K124 Active Safety Control Module via the communication enable circuits, except the K109
Frontview Camera Module which is powered directly by battery.
Media Oriented Systems Transport (MOST) Circuit Description
The MOST Infotainment network is a dedicated high speed multimedia streaming data bus independent from
GMLAN. The MOST bus will be configured in a physical hardwired loop with each device within the bus sends
and receives data on an assigned MOST addresses in a set order. Each device on the MOST bus will be required
to have twisted pair copper wires (2 transmit TX, 2 receive RX, and 1 electronic control line which is a 12 V
wakeup signal line). The A11 Radio is the MOST Master and will monitor the bus for vehicle configuration,
Infotainment data messages and errors on the bus. The MOST initialization consists of a short 100 ms low
voltage pulse on the electronic control line (or MOST control line) connected to all devices contained on the
MOST ring. When the MOST devices receive this wakeup message, they will respond with a generic device
response. Once these initial responses on the MOST bus are reported successfully without error to the A11
Radio, the next responses will report the MOST device addresses, their functionality requirements and
capabilities within. The A11 Radio will learn this information and also record the address node sequence on the
MOST bus at this point. This node address list will now be stored within the A11 Radio as the MOST bus
configuration (called "Last Working MOST ID of Node 1 - 9" on scan tool data display).
When MOST receive, transmit, or control line faults are detected, transmit/receive messages will not be
received as expected from the wakeup request. The A11 Radio and the K74 Human Machine Interface Control
Module will then perform diagnostics to isolate these MOST faults. If the MOST control line is shorted low to 0
V for excess amount of time, the A11 Radio will set a U2098 DTC and K74 Human Machine Interface Control
Module will set a U0029 02 DTC. At this point the MOST bus will be unable to communicate until the shorted
MOST control line is repaired.
Once the shorted MOST control line diagnostics pass, the A11 Radio will attempt to resend the initial short
pulse attempts up to 3 times on the MOST control line. If the expected responses are not received, the A11
Radio continues into a failure mode setting a U0028 DTC and will continue on to send 300 ms long pulses
while DTC U0028 is current, which will enable the furthest upstream transmitting device to become the
surrogate MOST Master in this MOST fault/diagnostic mode. When the A11 Radio receives this new MOST
Master identity, the surrogate MOST master device can be identified based on scan tool data parameter
"Surrogate MOST Master Node Upstream Position". The scan tool and schematics will be used to determine the
MOST bus configuration and direction by utilizing the "Last Working MOST ID of Node 1 - 9" parameters
from the A11 Radio data display. When a fault is present, it will indicate the newly enabled "Surrogate MOST
Master Node Upstream Position" to the A11 Radio. This will assist in determining the location of the MOST
device/bus/control fault. The MOST device and circuits upstream from the surrogate MOST master device,
transmit, receive, or control lines will be the suspect areas for diagnostics at this point. These faults can be
associated with any of the MOST transmit, receive, or control line twisted copper wires or possibly an internal
device fault.
DTC U0028 will take approximately 10 s for diagnostics to set in the A11 Radio with an active fault condition.
With the latest software, the A11 Radio will report the Surrogate MOST Master Node Upstream Position value
when DTC U0028 is stored in history. When there is no MOST bus fault, this value is None. The U0028 DTC
state and the Number of MOST Communication Breaks parameter must be used with the Surrogate MOST
Master Node Upstream Position parameter for a successful diagnosis. This is used to help capture surrogate
information on intermittent fault conditions. The Number of MOST Communication Breaks counter will
increment each time the MOST bus state transitions from Normal Operation (Lock status) to Off State (Unlock
status) and will accumulate from 0-65535. After the Number of MOST Communication Breaks counter
increments 10 times, DTC U0028 will be set. It is important to clear DTC U0028 and reset the Surrogate MOST
Master Node Upstream Position value to None after a successful repair. The Surrogate MOST Master Node
Upstream Position value can be reset to None by disconnecting the A11 Radio power, disconnecting battery
cables, or 50 ignition power down cycles. This will also reset the Number of MOST Communication Breaks
counter to 0.
The K74 Human Machine Interface Control Module will set a U0029 00 DTC when it diagnoses a MOST bus
not communicating properly after one attempt. When the DTC U0029 00 is set by the K74 Human Machine
Interface Control Module without the corresponding DTC U0028 from the A11 Radio, it will be an indication
of an intermittent wiring/device condition. The A11 Radio may also set a U0029 7F DTC if there is an
intermittent wiring/device condition.
Low Speed GMLAN Circuit Description
Low Speed GMLAN Bus is used in applications where a high data rate is not required which allows for the use
of less complex components. It is typically used for operator controlled functions where the response time
requirements are slower than those required for dynamic vehicle control.
The Low Speed GMLAN Serial Data Network consists of a single wire, ground referenced bus with high side
voltage drive. During on road vehicle operation data symbols (1's and 0's) are transmitted sequentially at the
normal rate of 33.3 Kbit/s. For component programming only, a special high speed data mode of 83.3 Kbit/s
may be used.
Unlike the high speed dual wire networks, the single wire low speed network does not use terminating resistors
at either end of the network.
The data symbols to be transmitted over the bus are represented by different voltage signals on the bus. When
the Low Speed GMLAN Bus is at rest and is not being driven, there is a low signal voltage of approximately
0.2 V. This represents a logic "1". When a logic "0" is to be transmitted, the signal voltage is driven higher to
around 4.0 V or higher.
Local Interconnect Network (LIN) Circuit Description
The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s.
This bus is used to exchange information between a master control module and other smart devices which
provide supporting functionality. This type of configuration does not require the capacity or speed of either a
High Speed GMLAN Bus or Low Speed GMLAN Bus and is thus relatively simpler.
The data symbols (1's and 0's) to be transmitted are represented by different voltage levels on the
communication bus. When the LIN Bus is at rest and is not being driven, the signal is in a high voltage state of
approximately Vbatt. This represents a logic "1". When a logic "0" is to be transmitted, the signal voltage is
driven low to about ground (0.0 V).
Communication Enable Circuit Description
Control modules on GMLAN high speed type networks enable or disable communication based on the voltage
level of this circuit. When the circuit voltage is high (around 12 V), communications are enabled. When the
circuit is low, communications are disabled.
Data Link Connector (DLC)
The data link connector (DLC) is a standardized 16-cavity connector. Connector design and location is dictated
by an industry wide standard, and is required to provide the following:
• Terminal 1: Low speed GMLAN communications terminal
• Terminal 2: Class 2 communications terminal
• Terminal 3: Object high speed GMLAN serial bus (+) terminal
• Terminal 4: Scan tool power ground terminal
• Terminal 5: Common signal ground terminal
• Terminal 6: High speed GMLAN serial data bus (+) terminal
• Terminal 7: Keyword communications terminal
• Terminal 11: Object high speed GMLAN serial bus (-) terminal
• Terminal 12: Chassis high speed GMLAN serial bus (+) terminal
• Terminal 13: Chassis high speed GMLAN serial bus (-) terminal
• Terminal 14: High speed GMLAN serial data bus (-) terminal
• Terminal 16: Scan tool power, battery positive voltage terminal
Serial Data Reference
The scan tool communicates over the various buses on the vehicle. When a scan tool is installed on a vehicle,
the scan tool will try to communicate with every control module that could be optioned into the vehicle. If an
option is not installed on the vehicle, the scan tool will display No Comm (or Not Connected) for that optional
control module. In order to avert misdiagnoses of No Communication with a specific control module, refer to
Data Link References for a list of control modules and the buses they communicate with. Use schematics and
specific vehicle build RPO codes to determine optional control modules.
Article GUID: A00884674
Data Communications - Diagnostic Information and Procedures - Volt
DIAGNOSTIC INFORMATION AND PROCEDURES
This list includes all Data Communications related U-code DTCs in alphanumeric order with descriptors for all
devices. Not all DTCs listed will be applicable to all vehicles.
|
For symptom byte information, refer to Symptom Byte List . | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|
DTC |
DTC Descriptor |
|
U010C |
Lost Communication with Turbocharger Boost Control Module |
|
U010E |
Lost Communication with Reductant Sensor Module |
|
U010F |
Lost Communication with Air Conditioning Control Module |
|
U0111 |
Lost Communication with Battery Energy Control Module |
|
U0112 |
Lost Communication with Battery Energy Control Module |
|
U0114 |
Lost Communication with Four Wheel Drive Clutch Control Module |
|
U0115 |
Lost Communication with Engine Control Module B |
|
U0117 |
Lost Communication With Power Take-Off Control Module |
|
U0121 |
Lost Communication With Electronic Brake Control Module |
|
U0122 |
Lost Communication With Vehicle Stability Control Module |
|
U0123 |
Lost Communication with Yaw Rate Sensor Module |
|
U0125 |
Lost Communication With Multi-Axis Acceleration Sensor Module |
|
U0126 |
Lost Communication With Steering Wheel Angle Sensor Module |
|
U0128 |
Lost Communication With Park Brake Control Module |
|
U0129 |
Lost Communication with Brake System Control Module |
|
U012A |
Lost Communication With Chassis Control Module |
|
U0130 |
Lost Communication With Power Steering Control Module |
|
U0131 |
Lost Communication With Power Steering Control Module |
|
U0132 |
Lost Communication With Suspension Control Module |
|
U0133 |
Lost Communication With Air Suspension Control Module |
|
U0134 |
Lost Communication with Power Steering Control Module - Rear |
|
U0136 |
Lost Communication With Differential Control Module - Rear |
|
U0137 |
Lost Communication with Trailer Brake Control Module |
|
U0139 |
Lost Communication With Suspension Control Module 2 |
|
U0140 |
Lost Communication With Body Control Module |
|
U0146 |
Lost Communication with Serial Data Gateway Module |
|
U0151 |
Lost Communication With Inflatable Restraint Sensing and Diagnostic Module |
|
U0154 |
Lost Communication with Passenger Presence Module |
|
U0155 |
Lost Communication With Instrument Cluster |
|
U0158 |
Lost Communication With Head-Up Display |
|
U0159 |
Lost Communication With Parking Assist Control Module |
|
U0160 |
Lost Communication With Chime Alarm Control Module |
|
U0164 |
Lost Communication with HVAC Control Module |
|
U0166 |
Lost Communication with Auxiliary Heater Control Module |
|
U0167 |
Lost Communication with Immobilizer Control Module |
|
U0168 |
Lost Communication With Keyless Entry Control Module |
|
U016B |
Lost Communication with Electric A/C Compressor Control Module |
|
U0170 |
Lost Communication with Passenger Presence Detection Sensor Module |
|
U017E |
Lost Communication with Seat Belt Retractor Motor Module |
|
U0181 |
Lost Communication with Automatic Headlamp Leveling Control Module |
|
U0182 |
Lost Communication With Lighting Control Module - Front |
|
DTC |
DTC Descriptor |
|
U0184 |
Lost Communication With Radio |
|
U0186 |
Lost Communication With Speaker Amplifier Module |
|
U0196 |
Lost Communication With Rear Audio Control Module |
|
U0191 |
Lost Communication With Television |
|
U0193 |
Lost Communication With Digital Radio Receiver Control Module |
|
U0197 |
Lost Communication With Telephone Control Module |
|
U0198 |
Lost Communication with Telematics Communication Interface Control Module |
|
U019E |
Lost Communication With Transmission Range Control Module |
|
U01A0 |
Lost Communication with Hybrid/EV Battery Interface Control Module 1 |
|
U01A1 |
Lost Communication with Hybrid/EV Battery Interface Control Module 2 |
|
U01A2 |
Lost Communication with Hybrid/EV Battery Interface Control Module 3 |
|
U01A3 |
Lost Communication with Hybrid/EV Battery Interface Control Module 4 |
|
U01A4 |
Lost Communication with Hybrid/EV Battery Interface Control Module 5 |
|
U01A5 |
Lost Communication with Hybrid/EV Battery Interface Control Module 6 |
|
U01A6 |
Lost Communication with Hybrid/EV Battery Interface Control Module 7 |
|
U01A7 |
Lost Communication with Hybrid/EV Battery Interface Control Module 8 |
|
U01B0 |
Lost Communication with Battery Monitor Module |
|
U01B4 |
Lost Communication with Brake System Control Module 2 |
|
U0201 |
Lost Communication with Passenger Door Switch Panel Control Module |
|
U0203 |
Lost Communication With Left Rear Door Switch Panel Control Module |
|
U0204 |
Lost Communication With Right Rear Door Switch Panel Control Module |
|
U0207 |
Lost Communication With Moveable Roof Control Module |
|
U0208 |
Lost Communication with Seat Memory Control Module |
|
U0209 |
Lost Communication With Front Seat Heating Control Module |
|
U0210 |
Lost Communication With Rear Seat Heating Control Module |
|
U0230 |
Lost Communication With Liftgate Control Module |
|
U0231 |
Lost Communication with Rain Sensor Module |
|
U0232 |
Lost Communication with Side Object Detection Control Module - Left |
|
U0233 |
Lost Communication with Side Object Detection Control Module - Right |
|
U0236 |
Lost Communication With Steering Column Lock Module |
|
U0237 |
Lost Communication With Multimedia Player Interface Module |
|
U023A |
Lost Communication With Vehicle Direction Camera Control Module (without |
|
Lost Communication With Active Safety Control Module 1 (with UGN) | |
|
U023B |
Lost Communication with Active Safety Control Module 2 |
|
U023C |
Lost Communication with Night Vision Camera Control Module |
|
U0241 |
Lost Communication With Left Headlamp High Beam Control Module |
|
U0242 |
Lost Communication With Right Headlamp High Beam Control Module |
|
U0248 |
Lost Communication with Remote Accessory Module |
|
U0249 |
Lost Communication with Rear Seat Entertainment Control Module |
|
U0250 |
Lost Communication with Impact Classification System Module |
|
DTC |
DTC Descriptor |
|
U0252 |
Lost Communication With Trailer Interface Control Module |
|
U0253 |
Lost Communication with Accessory Protocol Interface Module |
|
U0254 |
Lost Communication With Remote Start Module |
|
U0255 |
Lost Communication With Info Display Module |
|
U0256 |
Lost Communication With Infotainment Faceplate Control Module |
|
U0257 |
Lost Communication With Info Display Module/Infotainment Faceplate Control |
|
U0259 |
Lost Communication with Special Purpose Vehicle Control Module |
|
U025B |
Lost Communication with Special Purpose Vehicle Control Module "C" |
|
U025C |
Lost Communication with Special Purpose Vehicle Control Module "D" |
|
U0264 |
Lost Communication With Camera Module - Rear |
|
U0265 |
Lost Communication with Left Front Short Range Radar Sensor Module |
|
U0266 |
Lost Communication with Night Vision Camera |
|
U0268 |
Lost Communication with Right Front Short Range Radar Sensor Module |
|
U0269 |
Lost Communication with Front Long Range Object Sensor |
|
U026A |
Lost Communication with Frontview Camera Module |
|
U026B |
Lost Communication with Rear Short Range Object Sensor |
|
Lost Communication with Left Rear Short Range Radar Sensor Module | |
|
U026C |
Lost Communication with Right Rear Short Range Radar Sensor Module |
|
U026D |
Lost Communication with Rear Middle Short Range Radar Sensor Module |
|
U0284 |
Lost Communication with Active Grille Air Shutter 1 Motor Module |
|
U0285 |
Lost Communication with Active Grille Air Shutter 2 Motor Module |
|
U0293 |
Lost Communication with Hybrid/EV Powertrain Control Module |
|
U0298 |
Lost Communication with DC/DC Converter Control Module |
|
U029D |
Lost Communication with NOx Sensor 1 Module |
|
U029E |
Lost Communication with NOx Sensor 2 Module |
|
U02A3 |
Lost Communication With Particulate Matter Sensor Module |
|
U0301 |
Software Incompatibility with Engine Control Module |
|
U0302 |
Software Incompatibility with Transmission Control Module |
|
U0305 |
Software Incompatibility With Cruise Control Module |
|
U0315 |
Software Incompatibility with Electronic Brake Control Module |
|
U031C |
Software Incompatibility With Brake System Control Module 2 |
|
U0401 |
Invalid Data Received From Engine Control Module |
|
U0402 |
Invalid Data Received From Transmission Control Module |
|
U0403 |
Invalid Data Received From Transfer Case Control Module |
|
U0405 |
Invalid Data Received From Cruise Control Module |
|
U0414 |
Invalid Data Received From Four Wheel Drive Clutch Control Module |
|
U0415 |
Invalid Data Received From Electronic Brake Control Module |
|
U0416 |
Invalid Data Received From Vehicle Dynamics Control Module |
|
U0417 |
Invalid Data Received From Park Brake Control Module |
|
U0418 |
Invalid Data Received From Brake System Control Module |
|
DTC |
DTC Descriptor |
|
U0420 |
Invalid Data Received From Power Steering Control Module |
|
U0421 |
Invalid Data Received From Suspension Control Module |
|
U0422 |
Invalid Data Received From Body Control Module |
|
U0423 |
Invalid Data Received From Instrument Cluster |
|
U0424 |
Invalid Data Received From HVAC Control Module |
|
U0428 |
Invalid Data Received From Steering Wheel Angle Sensor Module |
|
U042B |
Invalid Data Received From Chassis Control Module |
|
U0431 |
Invalid Data Received From Body Control Module "A" |
|
U0432 |
Invalid Data Received From Multi-axis Acceleration Sensor Module |
|
U0437 |
Invalid Data Received From Differential Control Module - Rear |
|
U0438 |
Invalid Data Received From Trailer Brake Control Module |
|
U0447 |
Invalid Data Received from Central Gateway Module |
|
U0452 |
Invalid Data Received From Inflatable Restraint Sensing and Diagnostic Module |
|
U045A |
Invalid Data Received From Parking Assist Control Module "A" |
|
U0465 |
Invalid Data Received From Power Take-Off Control Module |
|
U0499 |
Invalid Data Received From Telematics Communication Interface Control Module |
|
U0513 |
Invalid Data Received From Yaw Rate Sensor Module |
|
U053B |
Invalid Data Received From Active Safety Control Module 1 |
|
U053C |
Invalid Data Received From Active Safety Control Module 2 |
|
U056B |
Invalid Data Received From Frontview Camera Module |
|
U0594 |
Invalid Data Received From Hybrid/EV Powertrain Control Module |
|
U063E |
Lost Communication with Exhaust Heat Exchanger Exhaust Bypass Valve |
|
U0656 |
Lost Communication with Turbocharger Boost Control Position Sensor |
|
U0657 |
Lost Communication with Turbocharger/Supercharger Bypass Valve "A" Position |
|
U1032 |
Lost Communication with Vehicle Dynamic Sensor 1 |
|
U1033 |
Lost Communication with Vehicle Dynamic Sensor 2 |
|
U1067 |
Lost Communication with Digital Map Control Module |
|
U1069 |
Lost Communication with Driver Monitoring System Control Module |
|
U106A |
Lost Communication with Multifunction Energy Storage Capacitor Control |
|
U106B |
Lost Communication with Multifunction Battery Isolator Control Module |
|
U1112 |
Lost Communication with Left Headlamp Leveling Device |
|
U1113 |
Lost Communication with Right Headlamp Leveling Device |
|
U1114 |
Lost Communication with Left Headlamp Vertical Motor |
|
U1115 |
Lost Communication with Right Headlamp Vertical Motor |
|
U1343 |
Chassis Control Module LIN Bus 1 |
|
U1345 |
Engine Control Module LIN Bus 1 |
|
U1347 |
Engine Control Module LIN Bus 3 |
|
U1359 |
Lost Communication with Transmission Range Indicator |
|
U135A |
Lost Communication with Shift to Park Range Actuator |
|
DTC |
DTC Descriptor |
|
U135B |
Lost Communication with Sunload Sensor |
|
U135C |
Lost Communication with Start-Stop Capacitor Control Module |
|
U135D |
Lost Communication with Transmission Control Module on Chassis Control Module LIN Bus 2 |
|
U135E |
Lost Communication with Transmission Control Module on Engine Control |
|
U1501 |
LIN Bus |
|
U1502 |
LIN Bus |
|
U1505 |
LIN Bus |
|
U1509 |
LIN Bus |
|
A26 HVAC Controls / P17 Info Display Module Lost Communication with K33 | |
|
U150E |
LIN Bus |
|
A22 Radio Controls / P17 Info Display Module Lost Communication with A11 | |
|
U150F |
LIN Bus |
|
A22 Radio Controls / P17 Info Display Module Lost Communication with K74 | |
|
K161 Vehicle Performance Data Recorder Lost Communication with K74 Human | |
|
U1510 |
A11 Radio Lost Communication with A20 Radio/HVAC Control / P17 Info |
|
K9 Body Control Module Lost Communication with B67 Ultrasonic Intrusion | |
|
K20 Engine Control Module Lost Communication with M96 Active Grille Air | |
|
K33 HVAC Control Module Lost Communication with A26 HVAC Controls / A20 | |
|
K33 HVAC Control Module Lost Communication with A34 HVAC Controls - | |
|
K39 Liftgate Control Module Lost Communication with K171 Hands-Free Liftgate | |
|
P16 Instrument Cluster Lost Communication with S70D Steering Wheel Controls | |
|
U1511 |
K20 Engine Control Module Lost Communication with M60B Active Grille Air |
|
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost | |
|
K40 Seat Memory Control Module Lost Communication with K99 Steering | |
|
K183 UHF Short Range Low Energy Remote Control Access Transceiver Lost |
|
DTC |
DTC Descriptor |
|
U1512 |
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost |
|
K124B Active Safety Control Module 2 Lost Communication with K187 Steering | |
|
K183 UHF Short Range Low Energy Remote Control Access Transceiver Lost | |
|
U1513 |
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost |
|
K183 UHF Short Range Low Energy Remote Control Access Transceiver Lost | |
|
U1514 |
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost |
|
K33 HVAC Control Module Lost Communication with A34 HVAC Controls - | |
|
K183 UHF Short Range Low Energy Remote Control Access Transceiver Lost | |
|
U1515 |
K9 Body Control Module Lost Communication with M75 Windshield Wiper |
|
K183 UHF Short Range Low Energy Remote Control Access Transceiver Lost | |
|
U1516 |
K9 Body Control Module Lost Communication with B110 Battery Sensor Module |
|
U1517 |
K9 Body Control Module Lost Communication with K62 Sunroof Sunshade Motor |
|
U1518 |
P16 Instrument Cluster Lost Communication with K78 Head-Up Display Module / |
|
U1519 |
K40 Seat Memory Control Module Lost Communication with S52 Outside |
|
K40 Seat Memory Control Module Lost Communication with K96 Mirror Control | |
|
U151A |
K9 Body Control Module Lost Communication with B117 Rain Sensor / B177 |
|
U151B |
K9 Body Control Module Lost Communication with K61 Sunroof Control Module |
|
K40 Seat Memory Control Module Lost Communication with S79P Window | |
|
U151C |
K33 HVAC Control Module Lost Communication with A34 HVAC Controls - |
|
DTC |
DTC Descriptor |
|
U151F |
A11 Radio Lost Communication with A20 Radio/HVAC Controls / A22 Radio |
|
U1520 |
K9 Body Control Module Lost Communication with P4 Security Siren / P25 Power |
|
K33 HVAC Control Module Lost Communication with M6CR Air Temperature | |
|
K40D Seat Memory Control Module - Driver Lost Communication with K134D | |
|
K40P Seat Memory Control Module - Passenger Lost Communication with K134P | |
|
U1521 |
K9 Body Control Module Lost Communication with S48E Multifunction Switch - |
|
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost | |
|
U1522 |
K9 Body Control Module Lost Communication with K65 Tire Pressure Indicator |
|
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost | |
|
K33 HVAC Control Module Lost Communication with M6UR Air Temperature | |
|
U1523 |
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost |
|
U1524 |
K9 Body Control Module Lost Communication with K29 Seat Heating Control |
|
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost | |
|
K33 HVAC Control Module Lost Communication with K10 Coolant Heater | |
|
U1525 |
K33 HVAC Control Module Lost Communication with K10 Coolant Heater |
|
U1526 |
K9 Body Control Module Lost Communication with K29R Seat Heating Control |
|
U1528 |
K33 HVAC Control Module Lost Communication with M37B Mode Door |
|
K40D Seat Memory Control Module - Driver Lost Communication with S64D | |
|
K40P Seat Memory Control Module - Passenger Lost Communication with S64P | |
|
U152A |
K33 HVAC Control Module Lost Communication with M6UL Air Temperature |
|
U152B |
K33 HVAC Control Module Lost Communication with K32 Steering Wheel |
|
DTC |
DTC Descriptor |
|
U152C |
K9 Body Control Module Lost Communication with K18 Compass Module on |
|
U152D |
K9 Body Control Module Lost Communication with P2 Transmission Shift Lever K33 HVAC Control Module Lost Communication with V1 Air Ionizer on LIN Bus |
|
U1530 |
K9 Body Control Module Lost Communication with M35P Window Motor |
|
U1531 |
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost |
|
U1532 |
K26 Headlamp Control Module / K28 Headlamp Leveling Control Module Lost |
|
U1534 |
K9 Body Control Module Lost Communication with M74D Window Motor - |
|
U1538 |
K9 Body Control Module Lost Communication with S79D Window Switch - |
|
U153A |
K9 Body Control Module Lost Communication with S79P Window Switch - |
|
U1540 |
K9 Body Control Module Lost Communication with M74RR Window Motor - |
|
U1544 |
K9 Body Control Module Lost Communication with M74LR Window Motor - Left |
|
U1548 |
K9 Body Control Module Lost Communication with S79LR Window Switch - Left |
|
U1549 |
K9 Body Control Module Lost Communication with M45 Rear Wiper Motor on |
|
U154A |
K9 Body Control Module Lost Communication with S79RR Window Switch - |
|
U154B |
K9 Body Control Module Lost Communication with K49 Rear Seat Control |
|
U1550 |
K9 Body Control Module Lost Communication with S31D Seat Heating and |
|
U1551 |
K9 Body Control Module Lost Communication with K33 HVAC Control Module |
|
U1555 |
K9 Body Control Module Lost Communication with S100LR Seat Heating/Venting |
|
U1556 |
K38 Chassis Control Module Lost Communication with K133 Trailer Brake Power |
|
U1558 |
K9 Body Control Module Lost Communication with S31P Seat Heating and |
|
U1559 |
K9 Body Control Module Lost Communication with K183 Short Range Remote |
|
U155D |
K9 Body Control Module Lost Communication with S100RR Seat |
|
DTC |
DTC Descriptor |
|
U156D |
K38 Chassis Control Module Lost Communication with S3 Transmission Shift |
|
U15E1 |
A11 Radio Lost Communication with A26 HVAC Controls / P17 Info Display |
|
U15F0 |
K74 Human Machine Interface Control Module Lost Communication with P17 |
|
A11 Radio Lost Communication with A20 Radio/HVAC Controls / A22 Radio | |
|
U15F1 |
K74 Human Machine Interface Control Module Lost Communication with K188 |
|
U15F3 |
K74 Human Machine Interface Control Module Lost Communication with K31 |
|
U1653 |
Chassis Systems High Speed Communication Enable Circuit |
|
U1725 |
Left Headlamp High Beam Control Module Lost Communication with Left |
|
U1726 |
Right Headlamp High Beam Control Module Lost Communication with Right |
|
U1727 |
Right Headlamp High Beam Control Module Lost Communication with Right |
|
U1728 |
Left Headlamp High Beam Control Module Lost Communication with Left |
|
U1729 |
Right High Beam Control Module Lost Communication with Right Headlamp |
|
U172A |
Left High Beam Control Module Lost Communication with Left Headlamp |
|
U1793 |
14V Power Module Lost Communication with Hybrid/EV Powertrain Control |
|
U1795 |
14V Power Module Powertrain Expansion Communication Bus Off |
|
U179A |
Lost Communication with Hybrid/EV Powertrain Control Module 2 |
|
U179C |
Lost Communication with One or More Hybrid/EV Battery Interface Control |
|
U179D |
Lost Communication with Brake System Control Module 2 on Chassis Expansion |
|
U1803 |
Lost Communication with Hybrid/EV Powertrain Control Module 2 |
|
U1804 |
Lost Communication with Inside Rearview Mirror Control Module |
|
U1806 |
Battery Energy Control Module High Voltage Energy Management CAN Bus Off |
|
U1807 |
Battery Charger Control Module High Voltage Energy Management CAN Bus Off |
|
U180A |
Electric A/C Compressor Control Module High Speed CAN Bus Off |
|
U180B |
Battery Energy Control Module High Speed CAN Bus Off |
|
U180C |
Battery Charger Control Module High Speed CAN Bus Off |
|
U180D |
Electronic Brake Control Module Chassis Expansion CAN Bus Off |
|
U1811 |
Battery Energy Control Module Powertrain Expansion CAN Bus Off |
|
U1814 |
Powertrain Wake-Up Communication Circuit |
|
DTC |
DTC Descriptor |
|
U1815 |
Lost Communication with Drive Motor Control Module 1 on Bus B |
|
U1816 |
Lost Communication with Drive Motor Control Module B on Bus B |
|
U1817 |
Lost Communication with Hybrid/EV Powertrain Control Module on Powertrain |
|
U1818 |
Lost Communication with Engine Control Module on Powertrain Expansion |
|
U1821 |
Lost Communication with 14V Power Module on Powertrain Expansion |
|
U1826 |
Lost Communication with Multi-Axis Acceleration Sensor Module on Powertrain |
|
U1827 |
Lost Communication with Steering Angle Sensor Module on Powertrain |
|
U182A |
Hybrid/EV Powertrain Control Module Lost Communication with Battery Energy |
|
U182D |
Lost Communication with Hybrid/EV Powertrain Control Module 2 on Powertrain |
|
U182E |
Drive Motor Control Module 1 Lost Communication with Hybrid/EV Powertrain |
|
U182F |
Drive Motor Control Module 2 Lost Communication with Hybrid/EV Powertrain |
|
U1831 |
Drive Motor Control Module 1 Lost Communication with Hybrid/EV Powertrain |
|
U1833 |
Lost Communication with Electronic Brake Control Module on Chassis Expansion |
|
U1838 |
Lost Communication with Battery Charger Control Module on High Voltage |
|
U1839 |
Auxiliary Transmission Fluid Pump Control Module Lost Communication with |
|
U183A |
Lost Communication with Telematics Communication Interface Control Module |
|
U183B |
Auxiliary Transmission Fluid Pump Control Module Lost Communication with |
|
U183C |
Auxiliary Transmission Fluid Pump Control Module Lost Communication with |
|
U183E |
Lost Communication with Telematics Communication Interface Control Module |
|
U1844 |
Battery Energy Control Module Lost Communication with Hybrid/EV Powertrain |
|
U1845 |
Drive Motor Control Module 1 Lost Communication with Hybrid/EV Powertrain |
|
U1846 |
Drive Motor Control Module 2 Lost Communication with Hybrid/EV Powertrain |
|
DTC |
DTC Descriptor |
|
U1847 |
Drive Motor Control Module 1 Lost Communication with Battery Energy Control |
|
U1849 |
Drive Motor Control Module 1 Lost Communication with Transmission Control |
|
U184A |
Lost Communication with Body Control Module on Low Speed CAN Bus |
|
U184B |
Lost Communication with Remote Heater and Air Conditioning Control Module |
|
U184C |
Lost Communication with Instrument Cluster on Low Speed CAN Bus |
|
U184D |
Lost Communication with Radio on Low Speed CAN Bus |
|
U184E |
Lost Communication with Inflatable Restraint Sensing and Diagnostic Module on |
|
U184F |
Electric A/C Compressor Control Module Lost Communication with Engine |
|
U1850 |
Drive Motor Control Module 2 Lost Communication with Transmission Control |
|
U1858 |
Electronic Brake Control Module Lost Communication with Hybrid/EV |
|
U185A |
Lost Communication with Battery Energy Control Module on High Voltage Energy |
|
U185B |
Battery Energy Control Module Lost Communication with Hybrid/EV Powertrain |
|
U185C |
Battery Charger Control Module Lost Communication with Hybrid/EV Powertrain |
|
U185D |
Fuel Injector Control Module Lost Communication with Engine Control Module |
|
U185E |
Fuel Injector Control Module Lost Communication with Body Control Module |
|
U1860 |
Electric A/C Compressor Control Module Lost Communication with Hybrid/EV |
|
U1861 |
Battery Charger Control Module Lost Communication with Engine Control |
|
U186A |
Electronic Brake Control Module Lost Communication with Engine Control |
|
U186B |
Electronic Brake Control Module Lost Communication with Transmission Control |
|
U1875 |
Drive Motor Control Module 1 Lost Communication with Battery Energy Control |
|
U1876 |
Drive Motor Control Module 1 Lost Communication with Engine Control Module |
|
U1879 |
Drive Motor Control Module 2 Lost Communication with Engine Control Module |
|
U1885 |
Battery Energy Control Module Lost Communication with Hybrid/EV Powertrain |
|
U1886 |
Battery Energy Control Module Lost Communication with Engine Control Module |
|
U1888 |
Hybrid/EV Powertrain Control Module Lost Communication with Battery Energy |
|
DTC |
DTC Descriptor |
|
U18A1 |
Lost Communication with Coolant Temperature Control Module on High Voltage |
|
U18A2 |
Lost Communication with Fuel Pump Driver Control Module |
|
U18A3 |
Lost Communication with Human Machine Interface Control Module |
|
U18A4 |
Lost Communication with Hybrid/EV Battery DC Charging Communications |
|
U18A5 |
Lost Communication with Fuel Injector Control Module on Powertrain Expansion |
|
U18A6 |
Lost Communication with Right Object Detection Control Module on Dedicated |
|
U18A7 |
Lost Communication with Power Supply Transformer on Powertrain Expansion |
|
U18A9 |
Lost Communication With Transmission Range Control Module on Chassis |
|
U18AA |
Transmission Range Control Module Lost Communication with Engine Control |
|
U18AB |
Transmission Range Control Module Lost Communication with Chassis Control |
|
U18AC |
Transmission Range Control Module Lost Communication with Chassis Control |
|
U18AD |
Transmission Range Control Module Lost Communication with Electronic Brake |
|
U18AE |
Lost Communication with Infotainment Control Touchpad on Dedicated Bus 1 |
|
U18AF |
Lost Communications With Telematics Communications Interface Control Module |
|
U18B0 |
Lost Communications With Instrument Cluster on Ethernet Bus |
|
U18B1 |
Lost Communications With Audio Amplifier on Ethernet Bus |
|
U18B2 |
Lost Communication with Rear Audio Control Module on Ethernet Bus |
|
U18B3 |
Lost Communications With Navigation Control Module on Ethernet Bus |
|
U18B4 |
Lost Communication with Radio on Ethernet Bus |
|
U18B5 |
Lost Communication With Hybrid Powertrain Control Module on Chassis |
|
U18B6 |
Lost Communication with Active Safety Control Module 1 on Chassis Expansion |
|
U18B7 |
Lost Communication with Active Safety Control Module 2 on Chassis Expansion |
|
U18B8 |
Lost Communication with Body Control Module on High Speed CAN Bus |
|
U18B9 |
Primary High Speed CAN Bus Subnet Configuration List |
|
U18BA |
Lost Communication with Power Steering Control Module on High Speed CAN |
|
U18BB |
Lost Communication with Power Steering Control Module on Chassis Expansion |
|
U18BF |
Secondary High Speed CAN Bus Subnet Configuration List |
|
DTC |
DTC Descriptor |
|
U18C0 |
Lost Communication with Suspension Control Module on High Speed CAN Bus |
|
U18C1 |
Lost Communication with Suspension Control Module on Chassis Expansion CAN |
|
U18C2 |
Lost Communication with Frontview Camera Module on Flexray Bus |
|
U18C3 |
Lost Communication with Video Processing Control Module on High Speed CAN |
|
U18C4 |
Lost Communication with Video Processing Control Module on Low Speed CAN |
|
U18C5 |
Lost Communication with Electronic Brake Control Module on High Speed CAN |
|
U18CA |
Lost Communication with Active Safety Control Module 1 on Flexray Bus |
|
U18CB |
Lost Communication with Active Safety Control Module 2 on Flexray Bus |
|
U18CC |
Transmission Range Control Module Lost Communication with ECM on |
|
U18CF |
Lost Communication with Active Safety Control Module 1 on High Speed CAN |
|
U18D0 |
Lost Communication with Active Safety Control Module 2 on High Speed CAN |
|
U18D1 |
Lost Communication with Transmission Range Control Module on Powertrain |
|
U18D2 |
Lost Communication with Transmission Range Selector Control Module on |
|
U18D3 |
Lost Communication with Transmission Range Selector Control Module on |
|
U1900 |
Lost Communication With Speech to Text Interface Module |
|
U1901 |
Lost Communication with Infotainment Multifunction Switch Module |
|
U2098 |
MOST Communication Enable Circuit |
|
U2099 |
High Speed Communication Enable Circuit |
|
U209E |
Object Detection Control Module High Speed Communication Enable Circuit 1 |
|
U209F |
Object Detection Control Module High Speed Communication Enable Circuit 2 |
|
U2100 |
CAN Bus Communication |
|
U2101 |
CAN Bus Maximum List of Control Modules |
|
U2103 |
Fewer Controllers On Bus Than Programmed |
|
U2105 |
Lost Communication with Engine Control Module |
|
U2106 |
Lost Communication with Transmission Control Module |
|
U2107 |
Lost Communication with Body Control Module |
|
U2108 |
Lost Communication with Electronic Brake Control Module |
|
U2125 |
Lost Communication with Telematic Unit |
|
U2127 |
Lost Communication with Front HVAC Control Module |
|
U2139 |
Lost Communication with Column Integration Module |
|
U2144 |
Lost Communication with Distance Sensing Cruise Control Module |
|
U216A |
Lost Communication with Front Object Detection Control Module |
|
DTC |
DTC Descriptor |
|
U216B |
Lost Communication with Rear Object Detection Control Module |
|
U2176 |
Lost Communication with Power Take-Off Control Module |
|
U2178 |
Lost Communication With Trailer Interface Control Module |
|
U2400 |
Fuel Injector Control Module High Speed CAN Bus Off |
|
U2401 |
Battery Energy Control Module Dedicated Bus 1 Off |
|
U2409 |
Transmission Range Control Module High Speed CAN Bus Off |
|
U240A |
Transmission Range Control Module Chassis Expansion CAN Bus Off |
|
U240B |
Radio Dedicated Bus Off |
|
U240D |
Transmission Range Selector Control Module Powertrain Expansion CAN Bus Off |
|
U240E |
Transmission Range Selector Control Module Powertrain Sensor CAN Bus Off |
|
U240F |
Transmission Range Control Module Lost Communication with EBCM on High |
|
U2410 |
Transmission Range Control Module Lost Communication with BCM on High |
|
U2411 |
Transmission Range Control Module Powertrain Expansion CAN Bus Off |
|
U2412 |
Reductant Control Module Powertrain Sensor Bus Off |
|
U2501 |
Invalid Data Received From Hybrid/EV Powertrain Control Module 2 |
|
U2502 |
Invalid Data Received From Electronic Brake Control Module on Chassis |
|
U2503 |
Invalid Data Received From Object Detection Control Module |
|
U2504 |
Invalid Data Received From Trailer Brake Driver Control Module |
|
U2505 |
Invalid Data Received from Human Machine Interface Control Module on MOST |
|
U2506 |
Invalid Data Received From Dual Battery Control Module |
|
U2507 |
Invalid Data Received from Instrument Cluster on MOST Bus |
|
U2508 |
Invalid Data Received from Audio Amplifier on MOST Bus |
|
U250B |
Invalid Data Received from Active Safety Control Module 1 on Chassis Expansion |
|
U250C |
Invalid Data Received from Active Safety Control Module 2 on Chassis Expansion |
|
U250D |
Invalid Data Received from Transmission Control Module on Chassis Control Module LIN Bus 2 |
|
U250E |
Invalid Data Received from Vehicle Dynamic Sensor 1 |
|
U250F |
Invalid Data Received from Vehicle Dynamic Sensor 2 |