Symptoms
- No beeping when reversing near objects
- Warning light for the sensor system stays on
- Sensors work inconsistently or only on one side
- Constant beeping even with nothing nearby
Likely causes
- CommonDirt, mud, or ice covering the sensorsSensors are small round discs in the bumper that need a clear surface to work.
- CommonBlown fuse for the sensor systemA dedicated fuse failure disables sensors without other symptoms.
- PossibleDisconnected sensor wiring after bodyworkBumper repairs or aftermarket accessories (like a hitch or wrap) can disconnect a sensor.
- PossibleFailed individual sensorOne sensor can fail while others continue working normally.
- Less commonSystem module faultThe control module for the whole system can develop an internal fault.
What to do
- Clean the bumper area around each sensor (small round discs) with a soft cloth and check for stuck debris.
- Check the fuse box for a blown parking sensor fuse and replace with the correct amperage.
- Turn the car on and listen near each sensor for a faint clicking, which indicates it's self-testing normally.
- If any sensor is silent during the self-test, note its location for repair.
- Check for any warning message on the dash specifically about the parking sensor system.
- If the car recently had bumper work done, mention this to a shop as a likely cause.
- Avoid relying solely on sensors while they're malfunctioning; use mirrors and a backup camera if available.
- Have a shop diagnose and replace the specific failed sensor or wiring.
Tools and parts
- Soft cloth
- Fuse puller or pliers
- Replacement fuses
Replacement parking sensorSearch: “parking sensor for [your car make model year]”
When to call a pro
Have a shop check for disconnected wiring first if the sensors stopped working right after a bumper repair or accessory installation.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.