The instrument panel cluster (IPC) illuminates the red brake warning indicator by supplying ground to the lamp. The EBCM sends a class 2 message to the IPC requesting illumination. The park brake switch is wired to the IPC logic. The red brake warning indicator also illuminates when the park brake is applied.
Step  | Action  | Yes  | No  | 
|---|---|---|---|
Schematic Reference: Brake Warning System Schematics and Instrument Cluster Schematics in Instrument Panel, Gages and Console  | |||
1  | Did you perform the Hydraulic Brake Diagnostic System Check?  | Go to Step 2  | |
2  | 
 Does the brake warning indicator illuminate for 3 seconds and then turn OFF?  | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems  | Go to Step 3  | 
3  | 
 Does the brake warning indicator turn OFF?  | Go to Step 4  | Go to Step 8  | 
4  | 
 Does the brake warning indicator turn OFF?  | Go to Step 6  | Go to Step 5  | 
5  | 
 Does the scan tool display On?  | Go to Step 9  | Go to Step 7  | 
6  | Replace the park brake switch. Refer to Parking Brake Indicator Switch Replacement in Park Brake. Did you complete the replacement?  | Go to Step 10  | --  | 
7  | 
 Did you find and correct the condition?  | Go to Step 10  | Go to Step 8  | 
8  | Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console. Did you complete the replacement?  | Go to Step 10  | --  | 
9  | Replace the EBCM. Refer to Electronic Brake Control Module Replacement in Antilock Brake System. Did you complete the replacement?  | Go to Step 10  | --  | 
10  | 
 Does the brake warning indicator illuminate for 3 seconds and then turn OFF?  | System OK  | Go to Step 3  |