GM Service Manual Online
For 1990-2009 cars only

When the park brake is applied, the park brake switch closes and a low (ground) condition exists at the BCM park brake input. If the ignition switch is in the RUN position or the START position, the BRAKE indicator illuminates in the instrument cluster.

If the vehicle is moved a distance of 10 to 50 feet with the park brake switch closed, an audible chime sounds.

When the brake fluid level is low, the brake fluid level switch closes and a low (ground) condition exists at the IPC brake fluid level input. If the ignition switch is in the RUN position or the START position, the BRAKE indicator illuminates in the instrument panel cluster and an audible chime sounds.

When the ignition switch is turned to RUN, the IPC performs a 5 to 7 second bulb check.