Test A: the Red Brake Warning Indicator Is Always on

Test A: The Red Brake Warning Indicator Is Always On

Refer to Vehicle/Diagrams, Instrument Cluster for schematic and connector information.

Normal Operation
The red brake warning indicator is located in the instrument cluster and illuminates when the brake fluid in the brake master cylinder reservoir is below a specific level, when the parking brake is engaged or when there is a failure with the anti-lock brake system (ABS) electronic brake force distribution (EBD) system (the yellow ABS warning indicator will also illuminate). The smart junction box (SJB) receives a ground input on circuit 1309 (RD/YE) when the parking brake has been applied through circuit 1205 (BK). The SJB then sends a standard corporate protocol (SCP) message to the instrument cluster to illuminate the brake warning indicator. The SJB provides a voltage reference signal to the brake fluid level switch through circuit 1305 (DB) and back to the SJB on circuit 128 (VT/YE). When the brake fluid level is low, the brake fluid level switch closes and connects circuit 1305 (DB) to ground along circuit 1205 (BK). Then the SJB sends a standard corporate protocol (SCP) message to the instrument cluster to turn on the brake warning indicator.

Possible Causes
^ Low brake fluid level
^ Brake fluid level switch
^ Parking brake engaged
^ Parking brake switch
^ Circuit shorted
^ Instrument cluster
^ SJB

A1:

A2-A5:

A6-A8: