Brake Fluid Level Input
WARNING: This page is about a different car, the 1988 Buick Riviera and 1988 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
Circuit No. 33 runs from the fluid level sensor in the reservoir to pin C1 on BCM connector No. 1. The switch is normally closed and opens the circuit between pins "A" and "B" if brake fluid gets low.