Diagnostic Instructions
Circuit/System Description
The instrument panel cluster (IPC) sees the brake fluid level switch input grounded and illuminates the red brake indicator. The body control module (BCM) sees the park brake switch input grounded, it sends a serial data message to the IPC requesting illumination
of the red brake indicator.
Reference Information
Schematic Reference
Hydraulic Brake Schematics
Connector End View Reference
Data Communication Connector End Views
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 ON. Verify brake lamp turns ON.
⇒ | If the brake lamp does not turn ON, replace the IPC. |
- Release the park brake. Disconnect the brake fluid level switch. Connect a 3-amp jumper wire between the signal circuit of the brake fluid level switch and the ground circuit of the brake fluid level switch. Ignition ON, verify the brake lamp is
ON.
⇒ | If the brake lamp does not turn ON, test the signal circuit and ground circuit for a high resistance/open or replace the brake fluid level switch. |
- Disconnect the park brake switch. Connect a 3-amp jumper wire between signal circuit of the park brake switch and ground. Ignition ON, verify the brake lamp is ON.
⇒ | If the brake lamp does not turn ON, test the signal circuit high resistance/open or replace the BCM. |
- Replace the park brake switch.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.