Rear parking sensors problem

[Johnbmwz4]

Hi, my parking sensors went a bit weird today. When reversing out of my drive they stared bleeping intermittently so I got out of the car to make sure there was nothing behind me and also gave the sensors a quick wipe. I got back in the car and everything was fine. When I got home I put it in reverse to park up and there was a constant bleep from the sensors then nothing even when I reversed up to my wall, so basically the sensors have stopped working for some reason. Any ideas guys?
Thanks

 

[owm]

Mine are exactly the same. Engage reverse and they will 'ding-ding' continuously even if there is an obstacle behind.

I did try to check by putting the car into ignition on mode, engage reverse gear and put my ear up against each sensor to hear if they click and all four are silent. Not sure if they are all dead or there is something else wrong.

Since the car is easy to park, fixing it is pretty low on my to-do list