Circuit/System Description

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

The brake pedal position (BPP) sensor is an input to the body control module (BCM). The BCM then sends a serial data message to the electronic brake control module (EBCM) and other electronic control modules. The BPP sensor is a potentiometer type sensor with 3 circuits: a 10-volt reference circuit, a low reference circuit and a brake apply sensor signal circuit. The BCM supplies the 10-volt reference to the BPPS. Varying the level of application of the brake pedal changes the BPPS voltage range from less than 1 volt to greater than 9 volts through the BPPS signal circuit. When the conditions for running this DTC are met, the BCM will use the brake fluid pressure sensor to determine if the predicted operating range of the BPPS voltage is correct. If the BCM detects the BPPS voltage is out of the predicted range, the BCM will send a class 2 message to the EBCM to set DTC C0161. The EBCM will set a DTC C0131 or C0132 for a brake fluid pressure sensor fault. The BCM will set DTC C0277, C0278, or C0283, and C0870.