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

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

I1-I4:

I4-I6:

I6-I7:

I8-I13:

I13-I17:

Normal Operation
The brake fluid level switch is hardwired to the anti-lock brake system (ABS) module through circuit 128 (VT/YE) and return circuit 512 (TN/LG). When the brake fluid level is low, the ABS module sends a command to the instrument cluster over the communication network to illuminate the brake warning indicator. The parking brake switch is hardwired to the smart junction box (SJB) through circuit 162 (LG/RD) and is grounded through the parking brake assembly. When the parking brake is applied, the SJB sends a command to the instrument cluster over the communication network to illuminate 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. If the instrument cluster loses communication with the ABS module, the instrument cluster illuminates the brake warning indicator.

Possible Causes
- circuit 162 (LG/RD) open or short to ground
- circuit 512 (TN/LG) open or short to ground
- parking brake switch
- brake fluid level switch
- ABS module
- instrument cluster