Parking Brake Position Switch

The parking brake position switch is hardwired to the Body Control Module (BCM) through a signal and return circuit. The Body Control Module (BCM) provides a battery reference voltage on the signal circuit. The return circuit is grounded internally in the Body Control Module (BCM). When the parking brake is not applied, the parking brake position switch is open. When the parking brake is applied, the parking brake position switch closes, pulling the reference voltage low.