Test H: Brake Warning Indicator Is Never/Always On

Pinpoint Test H: The Brake Warning Indicator Is Never/Always On


























Normal Operation
When the parking brake is applied, circuit CCBO9 (GY/BU), to the smart junction box (SJB), is grounded by the parking brake switch through circuit GD143 (BK/VT). The SJB receives the ground signal and sends the instrument cluster a message over the medium speed controller area network (MS-CAN) to illuminate the brake warning indicator. The brake fluid level switch is hardwired to the anti-lock brake system (ABS) module through circuits CMC19 (GY/VT) and RMC19 (YE/GY). The brake fluid level switch is grounded through circuit GD12O (BK/GN). The ABS module monitors the brake fluid level and when the brake fluid level is low or a base brake system concern is detected, the ABS module sends a signal to the instrument cluster over the high speed controller area network (HS-CAN) to illuminate the brake warning indicator.

Possible Causes
- circuit CCBO9 (GY/BU) open or short to ground
- circuit CMC19 (GY/VT) open or short to ground
- circuit GD12O (BK/GN) open
- circuit GD143 (BK/VT) open
- circuit RMC19 (YE/GY) open or short to ground
- parking brake switch
- brake fluid level switch
- SJB
- ABS module
- instrument cluster