Parking Sensors Problem

[seasiders1]

I have a 2009 T5 SE which was fitted with aftermarket front and rear sensors due to a dealer mix up. All was fine until last year. The back ones now go off continuously when I select reverse. However if it’s raining they work perfectly! I have resorted to a bottle of water spray before reversing, and have now worked out which one, of the four, is faulty (I think). Just wondered if anyone can help with how to fix it. Thanks.

 

[WelshGas]

I have a 2009 T5 SE which was fitted with aftermarket front and rear sensors due to a dealer mix up. All was fine until last year. The back ones now go off continuously when I select reverse. However if it’s raining they work perfectly! I have resorted to a bottle of water spray before reversing, and have now worked out which one, of the four, is faulty (I think). Just wondered if anyone can help with how to fix it. Thanks.

I would start by disconnecting each sensor, 1 at a time, normally there is a plug and socket for each sensor behind the bumper cover, and thoroughly clean the connections.
If that doesn't fix the fault then you may have to replace the faulty sensor, but that may be difficult if they are non-VW sensors and you are not sure of the make.