Chevrolet Trax: 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.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

When an OnStar keypress is made, a serial data message is sent to the audio system to mute all radio functions and output OnStar 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

• OnStar/Telematics Schematics (Encore), OnStar/Telematics Schematics (Trax)
• Radio/Navigation System Schematics (Encore), Radio/Navigation System Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

OnStar 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, 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 OnStar message is heard clearly through the audio system when the OnStar blue button is pressed.

If OnStar message is noisy or distorted

Refer to Circuit/System Testing

If OnStar message is heard clearly

4. All OK.

Circuit/System Testing

1. Ignition OFF and vehicle systems OFF, disconnect the X2 harness connector at the K73 Telematics Communication Interface Control Module, ignition ON.
2. Test for less than 4 V between each of the signal circuits listed below and ground:

• Terminal 1
• Terminal 2

If 4 V or greater

1. Ignition OFF, disconnect the X1 harness connector at the A11 Radio, ignition ON.
2. Test for less than 1 V between the signal circuits and ground.

• If greater than 1 V, repair the short to voltage in the circuit.
• If less then 1 V, replace the A11 Radio

If less than 4 V

3. Ignition OFF.
4. Test for infinite resistance between each of the signal circuits listed below and ground:

• Terminal 1
• Terminal 2

If less than infinite resistance

Repair the short to ground on the circuit.

If infinite resistance

5. Disconnect the X1 harness connector at the A11 Radio.
6. Test for less than 2 ohms in each of the signal circuits listed below end to end:

• K73 Telematics Communication Interface Control Module Terminal 1 X2
• K73 Telematics Communication Interface Control Module Terminal 2 X2

If 2 ohms or greater

Repair the open/high resistance in the circuit.

If less than 2 ohms

7. Replace the K73 Telematics Communication Interface Control Module.
8. Verify that the Connecting to OnStar message is heard clearly through the audio system when the OnStar blue button is pressed.

If audio is not heard clearly

Replace the A11 Radio.

If audio is heard clearly

9. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair procedure.

Control Module References for radio or telematics communication interface control module replacement, programming, and setup.

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