Parking Sensors

Ultrasonic sensors in the bumpers are most common. The beeping gets faster as the obstacle gets closer. Some cars use them for automatic parking. Most cars show the distance on the screen with coloured zones; front sensors usually activate only at low speed. Sensors are painted in body colour and repainting must follow the manufacturer's guidance on paint thickness.

Sensors send ultrasonic pulses and measure the echo time.

Dirt, ice or damage can cause false alarms. Thin poles or low objects may not be detected.