Rear passenger door lock not working - any ideas?

[stevem999]

Hi everyone, got a Passat B5, S Reg, 105k. Just recently the central locking seems to have been playing up. The rear passenger door lock wasn't always popping up and down, but now has stopped completely. I've looked at a lot of threads around the forum and can see mention of an ECU unit under the passenger footwell, and also resetting the central locking by undoing an earth lead off the battery (which lead is that, and how do I go about it?). There seems to be no mention of a lock unit failing so perhaps these are very reliable and not an issue?

As it's only 1 lock, it's odd that it might be a control unit etc but sure you can tell me otherwise. Any ideas, or info on new lock units (how much!!) would be appreciated.

[Hex69]

if you do a search for water leaks, you'll find what the problem is. Basically, water collects in the battery compartment when the bungs in it get blocked. it then runs into the car via the pollen filter area, soaking the Central Convenience Module which is under the passenger seat.

If it doesn't muck this up, it can corrode over time the wiring going to the module, causing the sort of problems you've noticed.

Resetting the central locking by undoing an earth lead off the battery (which lead is that, and how do I go about it?).

Easy, it's the black wire coming off the battery, though I've not heard of it resetting the c/l.

hope this helps.:biglaugh:

[B5-4ever]

I had similar problems last year with locks and power windows and started running my own troubleshooting. To date, I have gotten rid of all my problems.

Mine was not a clogged drain hole or a drowned convenience module. My lock problems turned out to be some really bad wiring in the B-pillar. Due to use and wear, the wiring had become all crispy and most of the lines (8 of 10) were broken.

Some soldering got the job done and now all my locks work. Surprisingly enough, my alarm also works again :-D

Pull off the weather protection from your pillar and inspect the wiring underneath. All wires are colour coded so it will be easy to find the right connections.

Good luck.

[macleod]

hi there i've had this problem for some months now not had any joy with sorting the problem totally dry under passenger seat which is the the b pillar?

[B5-4ever]

The B-pillar, that would be the column onto which the rear door is mounted.

Happy fiddling.

[macleod]

ok thanks

[Ham]

I had a similar fault with the front passenger door on our '02 Passat. In my case the fault was not with the ecu. Replacing the electronic module in the door solved the problem. Cost of the module was about £90 from the main dealer.
Rich.

[heedthebau]

I had the problem, disconnecting the battery for 30 Mins worked for me

[WesleyP]

I had the same fault, also Electric window not working. Bad connection in a junction block between door and B-Pillar

[mwvw]

Same as WesleyP - door not working - Undo rubber sleeve at the door push connectors firmly home and reconnect sleeve:D