I've recently gone through the same problem. If you look at the following thread PDC Failure you may be able to track down where the fault lies.

If you turn on the PDC function and then listen closely to each of the sensors in turn you should hear a ticking noise. If there is no sound then the sensor itself is causing the fault. It may be moisture related and you can try cleaning the sensor by spraying it librally with WD40. Some have found that this cured the problem. On my car I needed to replace it. I was lucky enough to find a new unused one on E-bay in the right colour, otherwise its off to the dealers plus a 6 week wait for them to supply one in the right colour.

Hope this helps.

 

Thanks for the link and guidance. Do you spray the WD40 onto the front of the sensor ?

I'll try the 'ticking' listening test today. Definately, seems to be moisture related in my case, Ok in dry, problem in wet.

Otherwise looks like a pain to get to the wires at the rear, I have M sport and I'm guessing this would mean taking bumper off.

 

I believe you spray the WD40 into the rings of the sensor to drive out the moisture, but hopefully someone else will chime in on this to confirm.

If its the outer sensor on the front bumper at fault you can get at it by popping the headlight out.

 

Hi I have replaced 2 sensors in the front bumber of my 535d touring and the one below the front lights will not work. I know the sensor is ok because when I swap it over for thr one beside the front grill it makes the clicking noises. Does this mean the connector or the wiring leading to it is the problem

 

Does anyone know if the PDC module enter in a protection stage like Light Module?
I have the error 9E3B PDC supply ultrasonic sensors short to negative

 

Can anyone recommend where to buy replacement sensors from? (E61 Touring). BMW originals seem to expensive (>£100 each?). There quite a few on eBay. I wondered if there is a retailer there that anyone knows is selling decent quality pattern parts,

thanks!

 

I wouldnt mind knowing the outcome to this as well?mloads in eBay but if they don't fit it's pointless.

My fronts are ok but my rear just comes up with PDC failure.