Hi guys. The rear parking sensors on my Audi A6 C7 have stopped working, and instead i just get a permanent beep sound whenever I put it in reverse. The parking sensor light inside the vehicle also flashes (instead of a permanent light) when this happens. I imagine it might just be a loose connection somewhere, any ideas? Or how I check the connections? Thanks.

Hello Dan,

Welcome, and thanks for joining. 
‘loose connection somewhere…’ - if only.
More likely to be one of the sensors is defective. Question is which one -? Some say you can detect which one by selecting reverse and putting your ear to each one in turn, and there should be a different tone. Does that work in practice?? Worth a try. 
It has also been said that a squirt of WD40 sometimes fixes the offending sensor. Will that work for you? 
If neither of these work, then it’s likely to be a case of getting it plugged in to find which of the sensors is defective. They may not all be the same across the car ( often different crank angles on the connector section) , so ask for the part number 
Once you have found the offender, Audi will want to extract probably north of £120/ sensor from your wallet.

Alternative:-have a look on EBay for the same part number, and buy one for less than £20 ( colour coded if you pay a bit extra). You might find it will come with the same Audi part number actually embossed on it - clever! 
Fitting:- some can be difficult to get at, and pessimistic situation is the bumper may have to be removed. 
Alternative issue ( but less likely) is that the actual module is at fault, but that would be much rarer.

Perhaps you could let us know how you get on Dan. 
Kind regards,

Gareth.