Circuit/System Description
WARNING: This page is about a different car, the 2008 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
The electronic brake control module (EBCM) supplies a 5-volt reference to the longitudinal accelerometer. When the vehicle is not moving, or is being driven at a constant steady speed, longitudinal acceleration is 0 m/sec/sec, and the longitudinal accelerometer signal voltage is very near 2.5 volts. This is referred to as longitudinal accelerometer bias voltage. Vehicle acceleration or deceleration causes the longitudinal accelerometer signal voltage to increase or decrease.