OnStar Audio Malfunction

OnStar Audio Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.

Diagnostic Fault Information





Circuit/System Description

When an OnStar(R) keypress is made, a serial data message is sent to the audio system to mute all radio functions and output OnStar(R) 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 Schematics (OnStar Schematics)
* Radio/Navigation System Schematics (Radio/Navigation System Schematics)

Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

OnStar Description and Operation (OnStar)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

Circuit/System Verification

1. Tune radio to a known good station and verify the audio is heard clearly through all speaker channels.

• If audio is not heard clearly, refer to Speaker Malfunction (Speaker Malfunction).

2. Ignition ON, radio ON, set volume to comfortable level and press OnStar(R) Call Center button. Verify Connecting to OnStar(R) message is heard clearly through the audio system.

• If OnStar(R) message is noisy or distorted, refer to Circuit/System Testing.

Circuit/System Testing

1. Ignition OFF, disconnect the X1 harness connector at the radio.
2. Ignition ON, test for a varying AC voltage between the following signal circuit terminals listed below and ground when the OnStar(R) Call Center button is pressed.

* Audio Signal Circuit- terminal 20
* Audio Common Circuit- terminal 6

• If AC voltage was not present, test the circuit for a short to voltage, short to ground, or an open/high resistance. If the circuit tests normal, replace the K73 telematics communication interface control module.

3. If all circuits test normal, replace the radio.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

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