OnStar Talk Button Inoperative

OnStar Talk Button Inoperative

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.



Circuit Description

The talk button switch in the headlamp switch housing is a redundant talk button control for the OnStar(R) system. When this button is used to initiate an OnStar(R) call, the body control module (BCM) gets the signal input from the button and then communicates over serial data to have the vehicle communication interface module (VCIM) perform the call function.


Reference Information
Schematic Reference

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

Component Connector End Views (Component Connector End Views)
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, press the talk button on the headlamp switch. Verify that a connection with OnStar(R) Call Center is not made.

If a connection with the OnStar(R) Call Center is not made, press the talk button on the OnStar(R) three button switch.
If the connection to the OnStar(R) Call Center is not made using the button on the OnStar(R) switch, refer to OnStar One or More Buttons Inoperative (OnStar One or More Buttons Inoperative) .
If the connection to the OnStar(R) Call Center is made using the button on the OnStar(R) switch, go to Circuit/System Testing.



Circuit/System Testing

1. Ignition OFF, with the scan tool observe the talk button switch data parameter in the BCM data list.
2. Verify that the data parameter changes from inactive to active when the headlamp switch talk button is pressed.

• If the data parameter changes from inactive to active, replace the BCM.

3. Disconnect the headlamp switch harness connector. Insert a fused jumper between terminal 10 and terminal 3.

• If the data parameter changed from inactive to active, replace the headlamp switch.

4. Ignition OFF, disconnect the BCM harness connector X2. Test for less than 5 ohms on the voice recognition signal circuit connector X2 terminal A13 and headlamp connector terminal 10.

• If greater than the specified range, repair the open/high resistance.

5. Test for less than 5 ohms on the low reference circuit BCM connector X2 terminal A10 and headlamp connector terminal 3.

• If greater than the specified range, repair the open/high resistance.




Repair Instructions

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

* Inside Rearview Mirror Replacement (Inside Rearview Mirror Replacement)
* Headlamp Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for radio replacement, setup, and programming