Circuit/System Description
WARNING: This page is about a different car, the 2007 Chevrolet Monte Carlo and 2007 Chevrolet Impala. However, it is still accessible from the selected car via links, so may be relevant.
The body control module (BCM) applies a ground through the brake pedal position sensor low reference circuit to the brake pedal position sensor (BPPS). The BCM supplies a 5-volt reference through the brake sensor reference voltage circuit to the BPPS. When the brake pedal is being applied, the BPPS then sends a variable voltage through the brake sensor signal circuit to the BCM.