Circuit Operation

The "BRAKE" Indicator, when lit, alerts the driver that the Parking Brake is engaged or that there is an insufficient amount of brake fluid in the Master Cylinder Reservoir. The "BRAKE" Indicator will also light when the Ignition Switch is turned to the BULB TEST position. If the vehicle is equipped with the Antilock Brake System (ABS), the Electronic Brake Control Module (EBCM) will turn on the "BRAKE" Indicator along with the "ABS" Indicator to alert the driver that there is a malfunction with the ABS which has affected the vehicle's base braking system.

Voltage to the "BRAKE" Indicator is provided through the IG-COIL Fuse. When the Parking Brake is engaged, the Parking Brake Switch is closed. Since the Parking Brake Switch is case grounded, a ground input is received by the Daytime Running Lamps (DRL) Control Module. The DRL Control Module, in turn, provides ground for the "BRAKE" Indicator. With both power and ground supplied, the "BRAKE" Indicator lights.

If the brake fluid level is low enough, then the Brake Fluid Level Switch, located within the Master Cylinder Reservoir, is closed. Since the Brake Fluid Level Switch is grounded at G102, the "BRAKE" Indicator will light whenever there is a low brake fluid condition.

The Bulb Test operation of the "BRAKE" Indicator occurs only when the Ignition Switch is turned to the BULB TEST position. When the Ignition Switch is turned to the BULB TEST position, ground is provided through the Ignition Switch to G203. With both power and ground supplied, the "BRAKE" Indicator lights.

If the vehicle is equipped with ABS and the "BRAKE" and "ABS" Indicators are lit simultaneously, then a ground has been provided to the "BRAKE" Indicator by the EBCM. Refer to Antilock Brake System in Brakes for diagnosis. Antilock Brakes / Traction Control Systems