Parking Assist Sensors
WARNING: This page is about a different car, the 2010 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
The parking assist sensors are located the in front and rear bumpers of the vehicle. The sensors are used to determine the distance between an object and the bumper. Each sensor emits an ultrasonic frequency which is reflected off object located behind the vehicle. These reflections are received by the sensors. The time difference between when the frequency was emitted and when the reflection is received, known as sensor ring time, is used to determine the distance to the object. The sensors report this information to the object alarm module.