Try disconnecting the sensors one at a time to see if you can narrow it down to one in particular.

 

Here is how I diagnose most parking sensor problems:

Put the ignition on and select reverse gear.
Go to the back of the car and very lightly move your finger tip back and forth across the face of each sensor.
You should feel the sensors pulse a little against you finger. The one that isn't pulsing is the faulty one.
If none are pulsing your fault is unlikely to be a simple sensor problem.

If you have thick skin (you need it on this forum ) and can't feel the sensors pulsing, you can touch a screwdriver blade onto the face of the sensors (being careful not to make the paint) then put your ear to the screwdriver handle and you should hear them ticking. Again, the one that doesn't tick is the faulty one.

I hope that helps you trace the problem.

Scottie.

 

Just learnt something. Being an ultrasonic sensor it makes sense they may be sensed by touch.

 

I have the same problem but there is no ticking or pulsing from any of the rear sensors.

 

Sounds like there is maybe a sensor power supply/ground problem in that case since that is what all the sensors have in common. There is usually a main harness connector for the rear bumper. That would be worth checking for signs of water ingress or other damage.

 

Many thanks I’ll check that out. 👍

 

Hi, have you fixed the problem? Cause now ive got the same issue.

 

My sensors pulse, but no sound in the car. What's the problem?

 

but no sound in the car. What's the problem?

Maybe the sounder is faulty.

 

I have now established that the system works for a bit, then doesn't. What could the problem be?