Side Object Sensors: Notes
WARNING: This page is about a different car, the 2010 Buick LaCrosse. However, it is still accessible from the selected car via links, so may be relevant.
The side object sensors are each located behind the rear fascia, positioned so that the sensor is pointing out toward the opposite lane. Each sensor is supplied B+ and ground. The right sensor receives an additional ground. Both sensors communicate independently on the serial data line. The serial data enters the left sensor in a pass-thru configuration, that connects to the right sensor. The scan tool is able to individually communicate with each sensor.
When a vehicle or object is detected by a side object sensor, the sensor will illuminate the indicator located in the appropriate outside rearview mirror.