GM Service Manual Online
For 1990-2009 cars only

Brake Warning Indicator

The instrument panel cluster (IPC) illuminates the brake warning indicator when one or more of the following occurs:

    • The body control module (BCM) detects that the park brake is engaged. The IPC receives a serial data message from the BCM requesting illumination.
    • The electronic brake control module (EBCM) detects a low brake fluid condition. The IPC receives a serial data message from the EBCM requesting illumination.
    • The electronic brake control module (EBCM) detects a closed brake pressure differential switch. The IPC receives a serial data message from the EBCM requesting illumination.
    • The EBCM detects an ABS malfunction which disables dynamic rear proportioning (DRP). The IPC receives a serial data message from the EBCM requesting illumination.
    • The IPC detects a closed power brake booster alarm switch and closed power brake booster fluid flow alarm switch. The IPC illuminates the brake warning indicator and sends a serial data message to the radio requesting the brake warning alarm.
    • The IPC performs the bulb check at the start of each ignition cycle. The brake warning indicator illuminates for approximately 3 seconds before turning OFF.
    • The IPC detects a loss of serial data communication with the BCM or with the EBCM.