XSeries-forum

I've read oodles of pages about the Parking Distance Control sensors but can anyone explain this...

I have a duff one on the rear all of a sudden. (3 second long tone followed by flashing green light on PDC button when engaging reverse.)
Did the quick test by turning them on at the witch and then putting my ear next to each one and all were clicking except one.
So I took it off and separated it from the plastic housing and found it was full of damp grit and mud.
Gave it a good clean and a wipe with GT85 (Water Displacer) and left it face up on a radiator overnight.
Next day, refitted it - and bingo -it was clicking again.
Sure enough, started the car, drove off and tried it - all working.
Then today, after the rain - but not being driven - I turned on and it failed again.

I've had a good look at it and it wasn't wet.

Can damp conditions alone effect these things?!

Looks like buying a new sensor is my only way to fix this. MORE dollar.

UrbanFlow, will keep a close eye on this thread, as I am suffering from the same...mine all seem to be ticking, but intermittently beeping with nothing near

If its had water in it it will be damaged, drying it out will have temporarily fixed it but will probably be damp inside again from water ingress or even condensation. The tiny components in the sensor will probably be corroding and will ultimately die completely. New sensors are not too expensive. I have 1 out on the front left of mine which I will replace when the weather is warmer. In the meantime I have turned the front sensors off with BMW scanner.

Internal corrosion makes sense.

I'm just going to swap it with the one next to it to check it isn't the wiring and then I think a new one might have to be bought. I can't keep taking it out and putting it on the radiator in the hall every night!

Just occurred to me that when I get my car washed I go for a hand car wash and they blast the car with jet washers to start with - I assume this is a big no-no near the sensors?

As long as there not blasted from short range you should be fine. I'm lazy to and take mine to the hand carwash too and then don't do any close range blasting, otherwise I would get out and tell them not too

Had this problem on my E90. The sensors are quite pricy from BMW. I bought a set of 4 off ebay secondhand for a fraction of the cost and I had spares!

Hope you have managed to sort the parking sensor, but if not......

From my experience, the only fix was to replace the dodgy sensor. I too had one that started causing problems intermittently throughout the winter periods. I thought I had got it sorted by drying it out, and it remained good until the following winter when the damper and cooler conditions killed it again.

I picked up a spare off ebay for about the third of the price of a new one from BMW - had no problems since (fingers crossed)

Michael.

[quote=""mrb0011""]Hope you have managed to sort the parking sensor, but if not......

From my experience, the only fix was to replace the dodgy sensor. I too had one that started causing problems intermittently throughout the winter periods. I thought I had got it sorted by drying it out, and it remained good until the following winter when the damper and cooler conditions killed it again.

I picked up a spare off ebay for about the third of the price of a new one from BMW - had no problems since (fingers crossed)

Michael.[/quote]

Well, it worked again after a night on the radiator and then went haywire again a few days later.

So I looked on Ebay and found a new one - cross checked the part numbers and bought it for £40. (They are over £80 new from BMW).
Works a treat now - all functioning again.