Test I: The Brake Warning Indicator Is Always On

PINPOINT TEST I: THE BRAKE WARNING INDICATOR IS ALWAYS ON

I1-I5:

I5-I8:

I9:

Normal Operation
The instrument cluster uses parking brake status and brake fluid level inputs to control the brake warning indicator. When the parking brake is applied, circuit 511 (LG) to the smart junction box (SJB) is grounded by the parking brake switch through circuit 57 (BK). The SJB receives the ground signal and sends the instrument cluster a message over the communication network to illuminate the brake warning indicator. When the brake fluid level is low, the brake fluid level switch closes, circuit 547 (LG/YE) is grounded to the SJB by the brake fluid level switch on circuit 57 (BK). The SJB receives the ground signal and sends the instrument cluster a message over the communication network to illuminate the brake warning indicator.

NOTE: When the anti-lock brake system (ABS) module detects an electronic brake distribution (EBD) fault, the ABS module sends a message to the instrument cluster. Whenever the instrument cluster receives an EBD message from the ABS module, the instrument cluster turns on both the brake warning indicator and the ABS warning indicator simultaneously.

Possible Causes
- Circuit 511 (LG) short to ground
- Circuit 547 (LG/YE) short to ground
- Parking brake switch
- Brake fluid level switch
- ABS concern
- SJB
- Instrument cluster