Hi all, about a month go I randomly got a PDC warning in the dash when I put the car in reverse. No big deal, probably a bust sensor.

So I was replacing the rear bumper anyways shortly aftre and the new bumper came with (used) sensors in it. While I had the bumper off I checked the wiring and cleaned all of the contacts. Refitted the new bumper and still the same issue. Every time I put the car in reverse I get the warning in the dash and nothing happens, no beeping etc.

I checked the code in the dash and its cc-Id 159, which google tells me means PDC Failure.

I'm thinking modules at this point so my question is does anybody know is there a way to check this is the problem? Would Carly/a proper non-dealer diagnostic be able to identify the exact issue or will I just keep getting generic codes and have to start throwing parts at it or bite the bullet and take it to a dealer for diagnostics?

The car is a 2007, non-idrive, PDC in the rear only.

All help greatly appreciated!!