Test K: The Brake Warning Indicator Is Never/Always On

PINPOINT TEST K: THE BRAKE WARNING INDICATOR IS NEVER/ALWAYS ON

K1-K4:

K4-K6:

K6-K9:

K9-K11:

K12-K15:

Normal Operation
The instrument cluster uses 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). When the brake fluid level is low, the FEM sends a command to the instrument cluster over the communication network to turn the BRAKE warning indicator on. The parking brake system is also monitored by the FEM. When the parking brake is applied, the parking brake switch closes to ground through circuit 91-RP9 (BN/GN). The FEM monitors the parking brake switch through circuit 9-RP9 (BN/GN). When the FEM detects that the parking brake is applied, it sends a command to the instrument cluster over the 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 communication network when a concern exists.

Possible Causes
- circuit 8-GC7 (WH/RD) open, or short to ground
- circuit 9-RP9 (BN/GN) open, or short to ground
- circuit 31-GC7 (BK) open
- circuit 91-RP9 (BN/GN) open
- parking brake switch
- brake fluid level switch
- ABS module
- FEM
- instrument cluster