OnStar Button Malfunction
OnStar 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
Circuit/System Description
The OnStar(R) button assembly consists of 3 buttons, Call/Answer, OnStar(R) Call Center, and OnStar(R) Emergency. The vehicle communication interface module (VCIM) supplies the OnStar(R) button assembly with 10 V via the keypad supply voltage circuit. Each of the buttons, when pressed, completes the circuit across a resistor allowing a specific voltage to be returned to the VCIM over the keypad signal circuit. Depending upon the voltage range returned, the VCIM is able to identify which button has been activated.
Reference Information
Schematic Reference
OnStar Schematics OnStar Schematics
Connector End View Reference
Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)
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 Control Module References for scan tool information
Circuit/System Verification
Note:
Contact the OnStar(R) Call Center first before pressing the emergency button in order to notify them of the test.
Ignition ON, press the OnStar(R) Call buttons one at the time. Verify that all of the OnStar(R) buttons operate normally.
If some OnStar(R) buttons are inoperative but not all, replace the OnStar(R) button assembly.
If none of the OnStar(R) buttons operate, refer to circuit/system testing.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the OnStar(R) button assembly.
2. Test for less than 10 omhs between the OnStar(R) button assembly ground circuit terminal E and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, test for less than 1 V between the keypad signal circuit terminal B and ground.
• If greater than the specified range, test the keypad signal circuit for a short to voltage. If the circuit tests normal, replace the VCIM.
4. Ignition OFF, test for 600k-800k omhs between the keypad signal circuit terminal B and ground.
• If less than the specified range, test the keypad signal circuit for a short to ground. If the circuit tests normal, replace the VCIM.
• If greater than the specified range, test the keypad signal circuit for an open/high resistance. If the circuit tests normal, replace the VCIM.
5. Ignition ON, test for 9.5-10.5 V between the keypad supply voltage circuit terminal A and ground.
• If less than the specified range, test the supply voltage circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the VCIM.
• If greater than the specified range, test the supply voltage circuit for a short to voltage. If the circuit tests normal, replace the VCIM.
6. If all circuits test normal, test or replace the OnStar(R) button assembly.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Communication Center Call Switch Replacement Service and Repair
* Control Module References Control Module References for VCIM replacement, setup, and programming