Test Q

PINPOINT TEST Q: THE BRAKE WARNING INDICATOR IS NEVER ON

Test Q1-Q3:

Test Q4-Q8:

Test Q9:

Normal Operation
The instrument cluster utilizes brake fluid level, engagement of the parking brake and the base brake system operation to provide inputs for the BRAKE warning indicator. The brake fluid level switch is hardwired to the front electronic module (FEM) through circuit 8-GC7 (WH/RD) and is grounded through circuit 31-GC7 (BK/BU). When the brake fluid level is low, the FEM sends a command to the instrument cluster over the standard corporate protocol (SCP) communication network, circuits 4-EG8 (GY/VT) and 5-EG8 (BU/WH), to turn on the BRAKE warning indicator. The parking brake system is monitored and controlled by the electronic parking brake module. When the parking brake is applied, the electronic parking brake module sends a command to the instrument cluster over the SCP communication network to turn on the BRAKE warning indicator. The ABS module monitors the brake pressures within the base brake system and provides a message to the instrument cluster over the SCP communication network when a concern exists.

Possible Causes
- circuit 8-GC7 (WH/RD) open or short to ground
- circuit 31-GC7 (BK/BU) open
- circuit 31S-RP9 (BK/GN) open or short to ground
- parking brake switch
- brake fluid level switch
- ABS/TC/IVD, ABS/TC, or ABS module
- FEM
- electronic parking brake module
- instrument cluster