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

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

P1-P4:

P4-P7:

P7-P9:

P10-P12:

P12-P13:

P14-P17:

P17-P20:

P20-P24:

P24-P28:

Normal Operation
When the parking brake is applied, circuit 1309 (RD/YE) to the smart junction box (SJB) is grounded by the parking brake switch through circuit 57 (BK). The SJB receives the ground signal and grounds circuit 977 (VT/WH) to the instrument cluster to illuminate the brake warning indicator. When the brake fluid level is low, the brake fluid level switch closes, sending a ground signal to the anti-lock brake system (ABS) module. The ABS module, in turn, provides a ground signal to the instrument cluster through circuit 22 (LB/BK) to illuminate the brake warning indicator.

Possible Causes
- circuit 22 (LB/BK) open or short to ground
- circuit 57 (BK) open
- circuit 977 (VT/WH) open or short to ground
- circuit 1309 (RD/YE) open or short to ground
- parking brake switch
- instrument cluster
- SJB
- ABS module