GM Service Manual Online
For 1990-2009 cars only

Brake

The brake system uses a single red BRAKE warning lamp located in the instrument cluster. When the ignition switch is in the START position, the BRAKE warning lamp should turn on. When the ignition switch is in the RUN position, the BRAKE warning lamp should turn off.

The following conditions activate the BRAKE warning lamp:

    • The parking brake is applied. The lamp should be on when the parking brake is applied and the ignition switch is ON.
    • The brake pressure differential warning switch detects a failure. Refer to Electrical Diagnosis for diagnosis.
    • The BRAKE warning lamp remains on while cranking the engine. This indicates that the circuit is operating properly.

Antilock

The Antilock Brake System (ABS) uses three indicator lamps:

    • The red BRAKE warning lamp
    • An amber ABS INOP indicator lamp
    • An amber LOW TRAC indicator lamp

The lamps operate normally under the following conditions:

    • When the ignition is turned to the RUN position, prior to starting the engine, the amber ABS INOP indicator lamp should turn on and the red BRAKE warning lamp should flash.
    • While the engine is cranked, the red BRAKE warning lamp and the amber ABS INOP indicator lamp should turn on. The amber LOW TRAC indicator lamp may turn on and off.
    • When the engine is started, the amber ABS INOP lamp and the red BRAKE lamp should turn off. The amber LOW TRAC indicator lamp may turn on and off.

The operation of the three lamps is an important part of the Antilock Brake System (ABS) diagnosis. A malfunction is present if the warning/indicator lamps turn on while driving the vehicle. If the warning lamps do not turn on under normal conditions as described above, service the lamps as soon as possible. For further information regarding the operation of the warning/indicator lamps for the Antilock Brake System (ABS), refer to Antilock Brakes.