Front PDC Acoustic Generator

[mccabema]

Hi all.

They're coming hard and fast this weather ! God damn !

Lastest fault I have is the front PDC acoustic generator (thing that beeps) is not functioning.

ALL PDC sensors are good

No fault code when I run a diagnostic

Green LED stays lit

Back Generator beeps just fine.

Any ideas as to where it is? It kicks in now and again...if I put my hand up to one of the front sensors.

Don't have any firends handy to help with locating it

Odd one to go I would have thought. Maybe its a faulty connector...

Thoughts and ideas greatly appreciated.

[x555]

Are you sure all the sensors are good....the reason i ask is that mine have been on the blink for a while and everytime i checked them they were all clicking away and a diagnostics scan came back the same with no fault code.
Then all of a suddden i got front middle right showing up on the scanner and again several times after (re tried every couple of days to make sure ) so i guess that sensor was good enough to generate a pulse/tick but must have been on the way out perhaps as the audiable tone came and went as well.

I will see tomorro as i'm gonna give the car a test run after some work i have done and then re scan it to check the pdc's aswell as i replaced that sensor tonight.

[mccabema]

Pretty sure !

I guess I'll have to wait for the sensor to go bad then in that case.

Hmmm,.. did have the battery out and installed a T91 there recently so maybe an unplug/reply in that area might reseat something that got disturbed !

Worth a shot considering the control is in that area.

[x555]

Worth a try I was on the lookout for a conrtol module for mine as i couldn't find a sensor wrong so presumed it was that anyway i'll let you know if mine is ok after a test tomorro

[mccabema]

So I checked all the connections in the boot today and also put my ear to all the front sensors, they are all clicking away.

I'm starting to think its the acoustic generator under the drivers foot well......the odd thing is, the chimes (such as washer fluid low or below 3c warnings) all come from the same generator, and they work just fine....and....if I have the PDC active and turn the ignition off, I get one single front PDC beep (the high pitched one).

I guess the only way I can rule out a faulty generator is to borrow one from someone else before replacing it.

[x555]

Well i tested mine today and after the umteenth time of re fitting the bumper they still don't work ...so it's either a duff sensor i have fitted (shouldn't be as it was new)or a faulty/corroded wire as i have been told by an indie that this is a common prob with them...ohh well back to the drawing board
BTW all of mine clicked aswell even though the scanner diagnosed one as faulty ....perhaps the module???

[x555]

Now i'm even more confused Had the bumper off again tonight (I'm thinking of replacing the bolts with velcro to m ake it easier )and re checked the new sensor to make sure it was pushed right in to the connector etc and check the wiring.
I then put the bumper back on temporarily, turned the key to ignition pos 2 and checked the rears and fronts and all were working fine bar the other front middle one which didn't beep at all.....but also didn't effect the others.
Question are the rears and fronts independant of each other as i think?
I also thought that when one sensor was bad that they all played up as they were linked i'm unsure now

Anyway they all worked other than the front middle left one after prancing about in front of them checking them so i re fitted the bumper,parked the car up and then ran a diagnostics scan which showed no faults ........until i went to pick my daughter up after and they went nuts again but then worked when i got home and reversed up the drive.............i give up for now ...all i can do next is replace the other iffy one and hope that sorts it.
I hate these ba$@rd things at the moment even if they are good when working

[Sanj]

I've always been lead to believe the front and rears are as 'one' but split by two control modules - front and rear. Could be total b*ll*x though!

x555 is it poss you have a faulty module - if there is one and you can find it?

Pure speculation on my part buddy.

[x555]

[quote=""Sanj""]I've always been lead to believe the front and rears are as 'one' but split by two control modules - front and rear. Could be total b*ll*x though!

x555 is it poss you have a faulty module - if there is one and you can find it?

Pure speculation on my part buddy.[/quote]

Thats what i originally thought that it could be the module which is in the boot some where AFAIK because i wasn't getting any faults on the sensors with the scanner?
Then i got the front right middle come up on several different occasions so changed that one yesterday/today (i also swapped it back again for the broken one tonight to eliminate the new one being duff if that makes sense ) and they seemed to work other than the front left middle which wouldn't beep at all !
I don't know if there's two modules (one for front and back)but i'm sure i have seen one in the boot or boot area.
number 1 here http://www.realoem.com/bmw/showparts.do ... g=66&fg=05

[x555]

mccabema do you know where the pdc module is located? or both if there's two? it may save me pulling out half the boot to investigate
Any help will be appreciated thanks.

[x555]

bump!

[mccabema]

Its in the boot -

Front left of the battery

[x555]

Thanks for that mccabema great stuff