Diagnostic Instructions
Circuit/System Description
The body control module (BCM) sees the park brake switch and brake fluid level switch input to grounded, it sends a serial data message to the instrument panel cluster (IPC) requesting illumination of the red brake indicator.
Reference Information
Schematic Reference
Hydraulic Brake Schematics
Connector End View Reference
Hydraulic Brake Connector End Views
Description and Operation
Brake Warning System Description and Operation
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List
Circuit/System Testing
- With the scan tool, select instrument panel special functions Lamp Test. Command the instrument panel lamps OFF. Verify brake lamp turns OFF.
⇒ | If the brake lamp does not turn OFF, replace the IPC. |
- Disconnect the park brake switch, with a scan tool observe park brake switch parameter. Verify parameter is reading ON.
⇒ | If parameter is OFF, replace the park brake switch. |
- Test the signal circuit of the park brake switch for a short to ground. Verify no short is found.
⇒ | If a short is found, repair the circuit. |
- Replace the BCM.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
Diagnostic Instructions
Circuit/System Description
The body control module (BCM) sees the park brake switch and brake fluid level switch input to grounded, it sends a serial data message to the instrument panel cluster (IPC) requesting illumination of the red brake indicator.
Reference Information
Schematic Reference
Hydraulic Brake Schematics
Connector End View Reference
Hydraulic Brake Connector End Views
Description and Operation
Brake Warning System Description and Operation
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List
Circuit/System Testing
- With the scan tool, select instrument panel special functions Lamp Test. Command the instrument panel lamps OFF. Verify brake lamp turns OFF.
⇒ | If the brake lamp does not turn OFF, replace the IPC. |
- Disconnect the park brake switch, with a scan tool observe park brake switch parameter. Verify parameter is reading ON.
⇒ | If parameter is OFF, replace the park brake switch. |
- Test the signal circuit of the park brake switch for a short to ground. Verify no short is found.
⇒ | If a short is found, repair the circuit. |
- Replace the BCM.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.