Circuit/System Description
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The instrument panel cluster (IPC) monitors the brake fluid level switch via the brake fluid level sensor signal circuit. With the switch closed, the signal circuit is pulled to ground indicating low fluid level. When low fluid level is seen, the IPC will illuminate the red brake warning indicator. The body control module (BCM) monitors the park brake switch via the park brake switch signal circuit. With the park brake applied, the switch is closed and the signal circuit is grounded. The BCM will then send a serial data message to the IPC requesting the red brake warning indicator be illuminated.