No (or Noisy) On Star Audio

No (or Noisy) On Star Audio

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 On Star(R) key press is made, a serial data message is sent to the audio system to mute all radio functions and output On Star(R) originated audio. After the audio system is muted, the communication interface module (CIM) transmits signals to the audio system on the cellular telephone voice signal and cellular telephone voice low reference circuits.

Reference Information
Schematic Reference

* On Star Schematics (On Star Schematics)
* Radio/Navigation System Schematics (Radio/Navigation System Schematics)

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

On Star Description and Operation (On Star Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

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 On Star(R) Call Center button. Verify Connecting to On Star(R) message is heard clearly through the audio system.

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

Circuit/System Testing

1. Ignition OFF, disconnect the X2 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 On Star(R) Call Center button is pressed.

* Audio Signal Circuit- terminal 7
* Audio Common Circuit- terminal 15

• 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 CIM.

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 CIM replacement, setup, and programming.