Replacing Front Inner PDC
 

Do I need to remove the front bumper to replace the front driver's side inner PDC (the one that fits in the number plate surround)? Or can it be accessed another way?

you dont have to remove it , just loosen it enough to get your hand in, still requires removal of inner wheel arch, undo the bolts in there enough to pull the bumper forward a little.

How can you test which one has failed? One of my rear ones doesn't work property. Is there any output tests on VCDS as it doesn't show any faults

vagcom tells you which one is faulty

Easy way is to listen to them, if it isn't ticking then it's failed

Cheers!

Update. Still no fault codes showing on VCDS, so found the measuring block in 001 for rear sensors. The inside rights sensors nearly always shows 0cm, but so times it will work and show 255cm and change as I reverse closer to something.

Will this be a wiring issue, or just a replacement sensor? Taking the bumper off sometime soon to have the exhaust tips painted and a dent removed so would be handy to have a replacement sensor then