Brake Warning Indicator Inoperative

Circuit Description
The BRAKE warning indicator lamp has two functions. First, it will light whenever the park brake is set. Second, a switch built into the brake master cylinder reservoir will signal the Electronic Brake Control Module (EBCM) if the brake fluid level drops below a safe level. The EBCM will command the indicator on via serial data with the instrument cluster. In addition, the indicator is commanded on when the EBCM is initially powered up (the ignition switch is turned to the RUN position). With the ignition switch in the OFF/UNLOCK or CRANK positions (loss of EBCM serial data), the indicator will also be illuminated.

Diagnostic Aids
The following conditions will activate the brake warning indicator:
^ An applied parking brake while the ignition switch is in the RUN position
^ A low fluid level in the master cylinder
Thoroughly inspect any circuitry that may cause an intermittent complaint for the following conditions:
^ Backed out terminals
^ Improper mating
^ Broken locks
^ Improperly formed or damaged terminals
^ Poor terminal-to-wiring connections
^ Physical damage to the wiring harness

Test Description
2. This test determines if the malfunction is caused by the IPC.
5. Ensure that the customer has not added brake fluid.