Parking assist systems almost exclusively use ultrasonic sensors. An ultrasonic sensor uses soundwaves to detect the distance to an object. The sensor sends out and receives the soundwave after bouncing off a detected object. The time it takes for the soundwave to return determines the distance the object is from the sensor. Due to how an ultrasonic sensor works, things like excess refinish material can impede the sensor’s ability to “hear”. For this reason, some OEMs restrict any repairs, which can include the amount of refinish material that can be applied or in some cases no refinishing the ultrasonic sensors.

Other things that can cause failures in the parking assist sensors can include mud, dirt, rain, snow, and stickers. Due to the fact that ultrasonic sensors use sound, loud noises near the vehicle can prevent the ultrasonic sensors from being able to hear as well.

To prevent impeding the ADAS's ability to function and potential failure, check OEM repair information to identify what restrictions may apply to the repairs you are considering. Always verify that the ADAS is functioning properly after completing repairs.

Additional I-CAR Collision Repair News you may find helpful:
ADAS, Calibration, and Scanning Article Hotspot
Understanding the Park Assist System
When ADAS Can't See