Parking Sensor (PDC)
Group: Chassis and safety
Parking sensors measure the distance to obstacles with ultrasound and warn you with beeps or on the screen. There are usually 4 to 6 per bumper.
Contents
What does the PDC sensor do?
Each sensor sends out an ultrasonic pulse and measures how long the echo takes to come back. The parking module calculates the distance to the obstacle and increases the beep rate as you get closer. On self-parking systems, the same sensors measure the available space.
Where is it located?
Set into the front and rear bumpers, painted to match the body.
Signal type and reference values
- 3 wires: supply (usually 8 to 12 V), ground and a signal or communication line to the module.
- Typical detection range: 25 cm to 1.5 m (about 10 in to 5 ft); some reach 2.5 m.
Values are a guide only: always check the manufacturer's data for your vehicle.
Symptoms of a bad PDC sensor
- Continuous beeping with no obstacle.
- A "parking system unavailable" message.
- One sensor does not detect obstacles in its zone.
How to test the PDC sensor step by step
- Clean the sensors: mud, ice or stickers cause false alarms.
- With the ignition on and reverse engaged, put your ear or a fingertip close to each sensor: a working sensor vibrates slightly or clicks faintly.
- Read the parking module with a scan tool: it reports which sensor has a fault.
- Check each sensor connector and the bumper wiring, especially after a minor collision.
Trouble codes related to the PDC sensor
Frequently asked questions about the PDC sensor
Can a parking sensor be painted?
Yes, with a thin coat of paint; a thick coat reduces its sensitivity.
Why does it only beep when it rains?
Water drops on the sensor reflect the ultrasound. If the warning goes away when it dries, the sensor is fine.
Updated September 25, 2026. Values are a guide only: always confirm them in the service manual for your engine.