Circuit/System Description
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) sends a serial data message when the brake pedal is applied. The electronic brake control module (EBCM) compares the brake pressure sensor values to ensure they agree with the brake pedal applied signal.