PDC Dodgy parking Sensor or module?

[sleepyfolk]

So forum genii, what’s going on here:

I read that if one sensor fails - the whole system goes down. I was getting the long tone and flashing light on the PDC switch after all the recent work, but before that the rear sensors sometimes beeped when there was nothing there.

I checked to see if they all clicked, and they did, although the rear left and centre left sounded weak.

I changed both of those (with eBay sensors) and they still sound weaker than the right rear and centre right, however All rear sensors beep if approached and stop when you move away, rear right seems to be the spurious one beeping occasionally at nothing.

On the front, they all click, the left front and centre left don’t beep at all when approached, centre right and right sensor work as normal.

So what is going on? I thought if they clicked audibly they were good, clearly not - do they get weak and fail to beep but still allow the system to work? I was thinking of changing the front 2 but I think it’s a bumper off thing so I don’t want to do it if you folk think it’s something else like a module or whatever else I don’t know about.

Just noticed on RealOEM that the corner ones seem to be right angled, the one I took out wasn’t, will this make a difference? There’s no part number for the right angled ones either!?

Sorry for the long post but I wasn’t sure if I’m wasting my time with eBay sensors, and if I take the bumper off apart from the hassle I’ll have to replace the underide protection for the radiator (another £50) and I’ve just spent a gert load this month already

[graemeX5]

Hi
Having a look at realoem all the sensors are the same it is just the sensor housing or support that will then mean they are seated at different angles.

If one is intermittent then that can cause it, do you have a scanner to check as it should help confirm that it is the that sensor.

Please see link below.
http://www.realoem.com/bmw/enUS/showpar ... Id=66_0009

On mine it was 2 at the front and a rear one that were faulty, but they can play up if you have washed the car and sprayed water or it's been icy that can affect their operation.

Graeme

[Alan Gunn]

I gave mine a spray of silicone stuff and  good wipe to clean the fronts.
Then pulled the plugs of and sprayed them then put them back on and off 2 or 3 times.
That sorted mine out.
Forgot to say it was when i first got the car and i had the beeeep and the flashing green light.

[sleepyfolk]

Thanks, I’ll pull the others out and see if it makes a difference before I replace any more, they do all tick away merrily already though

[henrym3]

I fitted e-bay sensors, 3 I think some 3 years ago and still working fine, any faults I've had has been cured by removing plug and spraying.

[nosignolife]

You can test the sensors too, engage reverse with the handbrake on, hop out and the car should pop into "N" neutral, leaving the system alive, (but faulty) go around the car and very VERY lightly touch each sensor, you should feel a pulsing coming from them, the one thats not pulsing is your problem. If they are all pulsing, or none are pulsing its the PDC control unit. Ive tracked a faulty sensor time and again using this method.For parts you could try Autodoc although be warned their delivery can be a bit random !
https://www.autodoc.co.uk

[A Blair]

Nice thread,
I have a PDC fault and I have it pencilled  it for May.  I have a question guys. When you scan do you get know which sensors are at fault or is it just pdc module error.

[Alan Gunn]

In pa-soft 1.4 it tell's you which sensors are faulty.

[A Blair]