E53 pdc problems

[Eddy e53]

Hi bought car couple of years ago just got around to trying to fix front parking sensors s fronts not working rears all good no clicking at all from all front sensors so took bumper off replaced all four wireing is good still no joy had a look at module in boot unplugged it all and cleaned put back in looks okay still nothing is there anything I’ve missed is there a connection anywhere from the front to inside off car apart from module as getting no clicking sound to front sensers might try buying diagnostics tool anyone know what type is best for pdc sensors

[henrym3]

When you took the bumper off did you inspect the wiring for breaks. It is easy to trap the wiring when replacing the bumper.
The front sensors are connected to a loom. Unplug the loom I think it’s f/r in engine compartment you can then check for continuity from the plug to the sensors and at least eliminate the front loom.
One other point my front sensors don’t automatically work if I drive up close to a wall or make any sound if I went out now and started up and checked them. My rears do. Fronts must be switched on at the dash if I want them to work. This has to be repeated on each start up or if I’m in a situation where I want them to work. ie tight parking.

[Eddy e53]

Yes have checked loom wireing all good I will turn on from dash and try that have not done that before thanks for your reply will get back to you soon as many thanks

[Eddy e53]

Hi have tested today activated pdc button no joy from fronts no power Going to them could it be the module unless there is some connection inside cr that is unplugged

[Eddy e53]

Might try and buy diagnostic tool as been quoted 80 pounds to look at problem anyone know of a good brand that covers pdc sensors

[X5Sport]

Unless there’s an error showing - blinking PDC light in the car, I’m not sure diagnostics will find anything as no error may be logged. £80 sounds the going rate for a code read. As for code readers, my suggestion would be to avoid generics due to them often only reading an error as a ‘P’ code rather than the true BMW hexadecimal code you need to diagnose faults. There are websites you can put the BMW Code into that will tell you where to look, although I have to admit even then the answers can be a bit uninformative!

Some folks on here use a Foxwell system, others have got themselves a copy of INPA/ISTA which is what BMW use but you need a laptop and some computer skills to use it. I use the Carly system with a wireless OBD2 dongle. That used to be a one-off purchase however it’s now an annual subscription. It works OK and has good support but is expensive - more than a code read.

My suspicion is that if the module was unplugged it may actually be the source of the fault. You may need to check the wiring for continuity to the boot. Any sign of water by the modules? You wouldn’t be the first to have suffered that particular evil!

[Eddy e53]

Hi thanks for reply the module was not unplugged sorry I just unplugged it and put it back in I don’t think there is yeah power At all going to front sensers

[X5Sport]

In that case and as suggested earlier wiring continuity probably worth a check. Have a search on the forum as well because this problem has come up before on E53s.

[henrym3]

Don’t forget if you do check continuity to have the ignition and the PDC switched on otherwise there will be no path from the module to the front sensors.

[Eddy e53]

Finally got around to front pdc not working was module in boot bought a used one with same part number all good now an working fine too old unit out of it s case and the only thing I could see was some white distcharge on back of chip board so maybe something has blown but any way all good now

[X5Sport]

Could also have been damp causing corrosion. These cars are almost ‘classics’ now - well the first ones are - so age and infirmity catching up with them (like the rest of us!).

Water in the boot electronics bay was not unheard of.