Circuit Description
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. 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 IPC sees the brake fluid level switch input grounded, it turns ON the red Brake indicator and sends a serial data message to the EBCM that tells the EBCM that the brake fluid level is low.