TIMM'S BMW E38
PARK DISTANCE CONTROL (PDC) REPAIR
If you have PDC fitted but all it does is
give a long 'beeeeeeeeeeep' when reverse is selected then you most likely have a
PDC sensor that has fizzled out. I heard a long while ago that you can hear them
click when they are working, so, ignition ON (don't start the engine) and press
the 'PDC' button. As long as it is reasonably quiet day you can hear the sensors
clicking by sticking your ear right up to each sensor.
Some sensors are slightly louder than others but it is reasonably easy to tell which ones are working and which ones aren't.
OK, so I have one dud at the front and one dud at the rear. I must say that I didn't fancy this one but it was a LOT easier than expected. This is how the rear trim comes off:
The TIS calls for a 'Hardwood wedge', well, half of Gypsy Roses' clothes peg seemed to do the trick. I just wedged it in there and the black rubbery trim along with the chrome top-strip came out nicely. There are around 8 clips top and bottom, they just pull out, here's the trim half off:
Before we go any further, this is what a PDC sensor looks like:
They are Part # 66-21-6-902-182 from BMW and usually around £48, as usual Ebay came up with a couple of new ones for a lot less!
I thought these things just poked into the rubbery trim but of course, being a BMW they actually have a plastic carrier built into the trim:
As you can see, this one is half out of the carrier and you can see that the lugs on the side of the PDC clip into securing tabs on the side of the carrier. You just open up these tabs a bit and push it out from the front of the sensor (they get a bit gummed in so a good poke is required). Once it is out you can release the PDC sensor from the loom, there is a catch on one side of the connector:
Fit the loom to the new sensor, make sure the little clip is engaged on the connector and just poke it back in the carrier until it goes 'click' and is flush with the trim.
The trim just pushes back on, make sure you go along the bottom of the trim a push quite hard where each clip is, they will snap into position securely. Here is a picture of what is under the trim, you can see the slots where the clips go in:
The rear sensors are quite easy to do and only take a few minutes. The front ones are a bit harder but still reasonably straight-forward.
First, remove the headlight on the corner where the faulty sensor is:
Having done this three times now I can get the headlight off in less than 5 mins! This gives good access to the back of the PDC sensors. If you have an exceptionally fat arm then you can remove the headlight carrier which is held on by two bolts. One thing to be careful of is that the carrier looks like it initially sets the headlight mounting position........I would have guessed that the headlight carrier is fitted to the headlight in Production, the headlight fitted to the upper mounts and then the carrier bolted down, all done before the front bumper is fitted. So, mark the positions of the fixing before removal so it goes back in the same place.
Fortunately I have skinny arms:
It is reasonably easy to winkle the PDC sensors out from here once you know how they unclip, here is the carrier still in place, this must be glued to the trim in Production and does not come off:
The PDC sensor on the corner trims can be reached from here as well, just ensure that you keep the sensor on the loom until you replace it, it is a lot easier connecting the loom while the sensor is out!
All done, time for a cup of tea............