Test L: The Brake Warning Indicator Is Always On

PINPOINT TEST L: THE BRAKE WARNING INDICATOR IS ALWAYS ON

L1-L2:

L2-L6:

L6-L7:

L8-L9:

Normal Operation
The brake warning indicator illuminates when the parking brake is applied, the brake fluid level is low, the switch is disconnected, an electronic brake distribution (EBD) concern exists, or there is a loss of communication between the anti-lock brake system (ABS) module and the cluster. The instrument cluster receives the parking brake input through circuit 162 (LG/RD). When the parking brake is applied, the parking brake switch closes to ground through circuit 57 (BK) and the instrument cluster illuminates the brake warning indicator. The instrument cluster provides a reference signal to the brake fluid level switch through circuit 531 (DG/YE) and a return on circuit 512 (TN/LG). The brake fluid level switch is grounded through circuit 57 (BK). When the brake fluid level is low the brake fluid level switch closes to ground and the instrument cluster illuminates the brake warning indicator. When the brake fluid level switch is disconnected, the brake fluid level switch is grounded through the signal return circuit 512 (TN/LG) and the instrument cluster illuminates the brake warning indicator. When an EBD concern is detected, the anti-lock brake system ABS module sends a command to the instrument cluster over the communication network and the instrument cluster illuminates the brake warning indicator. If a loss of communication between the ABS module and the instrument cluster exists, the instrument cluster illuminates the brake warning indicator.

NOTE: When the ABS module detects an 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 162 (LG/RD) short to ground
- Circuit 512 (TN/LG) open or short to ground
- Circuit 531 (DG/YE) open or short to ground
- Parking brake switch
- Brake fluid level switch
- Instrument cluster