"Brake" Indicator Control: Notes
WARNING: This page is about a different car, the 1990 Buick Riviera and 1990 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
When the brake lamp is inoperative always test the bulb first.
With the ignition switch in Run, Bulb Test, or Start, voltage is applied through CPS fuse 5 to the brake indicator. The circuit is completed to ground by the controller in the instrument panel cluster to light the brake indicator. The indicator is lit briefly by the controller at ignition. This acts as a lamp test for the indicator. The BCM signals the instrument panel cluster to light the brake indicator through the data line. This occurs when one or all of the following conditions exist.
- The Park brake Switch Closes
- Brake Fluid Level Switch Closes
- The Hydraulic Pressure Switch Closes