OnStar Talk Button Malfunction

OnStar Talk Button 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





Typical Scan Tool Data





Circuit/System Description

The OnStar(R) talk switch, if equipped, is incorporated with the headlamp switch. The body control module supples a B+ input signal to the switch. When the switch is pressed, the signal is pulled low through the switch to the headlamp switch low reference circuit in the body control module. When the body control module senses the signal is pulled low, a serial data message is sent to the communication interface module to start voice interaction with the OnStar(R) system.

Reference Information
Schematic Reference

* OnStar Schematics (OnStar Schematics)
* Headlights/Daytime Running Lights (DRL) Schematics (Headlights/Daytime Running Lights (DRL) Schematics)

Connector End View Reference

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

OnStar Description and Operation (OnStar 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, observe the body control module scan tool talk switch input parameter while pressing and releasing the talk switch. The reading should change between inactive and active.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the headlamp switch.
2. Verify a test lamp illuminates between the low reference circuit terminal 3 and B+.

• If the test lamp does not illuminate, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the body control module.

3. Ignition ON, verify the body control module scan tool talk switch input parameter is inactive.

• If not the specified value, test the signal circuit terminal 10 for a short to ground. If the circuit tests normal, replace the body control module.

4. Install a 3A fused jumper wire between the signal circuit terminal 10 and the low reference circuit terminal 3. Verify the body control module scan tool talk switch input parameter is active.

• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the body control module.

5. If all circuits test normal, replace the headlamp switch.

Repair Instructions

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

* Headlamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for body control module replacement.