E30 Zone

I have suffered the old central locking failure three times now, each time I replace the control unit behind the speaker in the drivers footwell, and each time it works fine for a while......then stops again.

Usually, before it packs up completely it starts unlocking the doors after I've locked them, so I end up using the key and deadlocking it just to be sure. Unfortunately, now that the control unit has packed up again, I can only get in the drivers door......and the lock on it has just packed up meaning I can't lock my car!

When I have replaced the control unit in the past, it has looked a bit damp, just wondering if there is a common leak point that I can sort out in the hope that it stops my central locking packing up all the time?

Also, anyone have any ideas about the drivers door lock, it just doesn't quite 'catch' when trying to lock, it was stiff for a while before it bust. Repairable or replace?

Dan

Dan,

It's little fiddly to do, but you can get a lock repair kit from the dealer. Rebuilding the lock also allows you to keep matching keys.

BMW part No: 51 21 9 061 344 for the drivers door, and 51 21 9 061 343 for the passengers door.

Good repair article on the central locking here:

http://www.e30zone.co.uk/modules.php?na ... ocking.htm

Article on lock rebuilding here:

http://www.bmwe30.net/cgi-bin/datacgi/d ... Section=01

As for the dampness, it may just be the drain holes in the front of the sill that are blocked. You will find that the sunroof drains drop their load just underneath the control unit. If the drains in the sill are blocked, the water has nowhere to go.

Ian.

Ian,

Bit of an odd place for the sunroof drains to drop their load, are they meant to do that??! I'll check the sill drain hole tomorrow.

As for the lock, thanks for all the info, looks like a very fiddly job, would it be less of a ball ache to just replace the drivers door lock and the ignition barrel....and carry two keys till I have the time to relace the passenger side and tailgate locks?

Dan

Can you smell a burnt smell? This may not be what has happened to you, but on my 90 model all the actuators burnt out and seized, and this caused the control unit to fail. It was a real bastard as we were away with all our luggage in the car and we couldn't get into car! So I yanked out all the seized actuators and don't have cental locking. One day I will replace them, but I think it will be expensive.

Have you ever tried reusing one of the discarded lock control units to see if it has come back to life?
In my experience, central locking problems are caused by the plug and socket in the driver's door pillar where the door wiring plugs in. If the rubber boot hasn't been fitted properly, water gets into the pins and their sockets and causes corrosion. You will have disturbed the wiring to this plug and socket from behind every time you remove the locking control unit.
The locking locks and immediately unlocks if it thinks the drivers door is open

Bloodt actuator went on mine changed it today seemed ok then it wouldnt unlock passenger on rear doors. now its working again. its bugging the life out of me as i only got one actuator left. time to find some breakers for some spares i think

Not had any burning smell. When the central locking unlocks itself immediately after having locked, I found it is due to my internal drivers door handle not 'retracting' fully.......if thats any help?!

Dan

This is really weird, I wass going to post the very same problem

All of a sudden my central locking has packed in, get a buzzing noise coming from the footwell when I lock the car but the passenger door doesn't lock.

Might add that I have just had an alarm fitted the other day which was wired for remote locking, is it a possability that this has 'caused the central locking failure, in particular if the rubber boot on the pillar wasn't connected properly?

Cheers
psSorry for hijacking this thread but didn't seem much point in posting kinda the same problem

No problem, I wouldn't call it a hijack exactly! I had the buzzing sound as well, but only for a day or two and then it seemed to give up completely. Not any help to you....but at least you're mot alone!

ian332isport wrote: Article on lock rebuilding here:

http://www.bmwe30.net/cgi-bin/datacgi/d ... Section=01

It must be a case of the locks coming to the end of their natural life as mine has the same problem...central locking went a couple of months ago (actuator) and now the lock is getting verrry dodgy...almost to the point where I can lock it by turning the key 90deg left and removing the key but to unlock it again is the probloem as the key won't turn fully back up to the vertical position so's I can unlock it.....

However, due to the zealots in charge of my net access at work (don't have it at home), the above link is blocked. Can someone do me a favour and copy and paste the page into an email or a PM for me please ?

Ok I have now stripped out my central locking relay as per the tech article but I have another relay (more like an indicator/hazard) relay next to the one pictured in the tech article, any ideas?

It isn't half corroded though, plentyof water ingress in that part of the car, over 15 years worth I think


Cheers

Al

The small 'relay' next to the locking control unit is the switch off delay unit for the interior lights.
If it's seriously wet in there, then you have problems with water leaking in/ not getting out of the cills. Check the front of the cill cavity isn't rusted through at the back of the wheelarch, and that the drain slots along the bottom of the cill are clear, and that the sunroof drain tubes reach the bottom of the cill.

Hi Brian

Cheers for the advice, I am waiting to get both relays replaced then I will seal them both up properly.

I poked about(lightly) with my screwdriver to try unblock the sill drain holes which I think I have done but they weren't half blocked with muck and a lot of something else!!!

Cheers once again

Al

Is it a bad idea to stick the the control unit in an uninflated balloon or something similar (to keep the water out).....or does the unit produce some heat?

Dan

Would have thought you could relocate it to above the removable panel above the driver's legs without to much effort, but BMW don't make many design mistakes. If BMW thought it was OK in the cill, then it should be allright there. You have some kind of problem getting excess water in there, or not letting it out.