Navigation System - Voice Guidance Inoperative or Degraded Quality

Navigation System - Voice Guidance Inoperative or Degraded Quality

Diagnostic Instructions

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

Circuit/System Description

The vehicle navigation radio and OnStar(R) system both utilize the cellular microphone to receive voice commands. The navigation radio receives an audio voice signal from the communication interface module (CIM).

Reference Information
Schematic Reference

Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Radio/Audio System Description and Operation (Radio/Audio System 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

Ignition ON, verify the OnStar(R) voice recognition is operating normally.

If the OnStar(R) voice recognition is inoperative, refer to OnStar Microphone Inoperative - Caller Cannot Be Heard (OnStar Microphone Inoperative - Caller Cannot Be Heard).

Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the CIM.
2. Ignition ON, test for 8.5-9.5 volts between the mono out signal circuit terminal 1 and ground.

• If less than specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
• If greater than specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio.

3. Ignition OFF, test for less than 10 ohms between the mono out low reference circuit terminal 2 and ground.

• If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the radio.

4. Ignition ON, test for 8.5-9.5 volts between the mono out signal circuit terminal 1 and the drain wire circuit terminal 8.

• If less than specified range, test the drain wire circuit for a short to voltage or an open/high resistance.

5. Ignition OFF, disconnect the X2 harness connector at the radio.
6. Verify that a test lamp does not illuminate between B+ and the mono out low reference circuit terminal 15.

• If the test lamp illuminates, test the low reference circuit for a short to ground.

7. If all circuits test normal, replace the CIM.

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