Circuit Description
WARNING: This page is about a different car, the 2003 Pontiac Sunfire and 2003 Chevrolet Cavalier. However, it is still accessible from the selected car via links, so may be relevant.
The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the BCM sees the brake fluid level switch input grounded, it sends a serial data message to the IPC requesting illumination of the red Brake indicator.