I fixed my central locking

[orkboss]

I fixed it tonight and I was surprised that I found the fault. As everyone can guess the fault was with the central locking module.
The symptoms were unusual in that it would not activate the central locking to lock on the key but it would unlock. Even more annoying was that it had the habit of locking itself both when driving along and when parked. I had to be very conscious of not leaving my keys in the car.
My first approach was to look at the connection between the car door and A frame and while I was at it have a look at the module to see anything wrong there.

Pulling the door connection apart I did notice only one pin with some green to indicate damp and corrosion but it was not much. I sprayed the connection heavily with WD 40 and rejoined it.

Next I took out the module and I could see nothing wrong with it, It looked fine. So I sprayed the pins with WD40 and put it all back together and tried the door lock. No joy still only the divers lock was the only one turning on the barrel. No central locking.

I left it for a few days noticing that there wasn't much self locking as there used to but it still occurred. I was expecting to take the door panel apart to see what I could do there.

Reading through the forum I notice so many referred to the module being the route of the problem and as I had my tourer sitting to be cannibalised I thought I would just try a different module as I knew for sure this one worked. And it did. No problems although I did notice a strange beep when I locked the car which has never happened before. It only beeped for four times but it seems to have stopped now whatever it was.

I took the old module apart but I can still see nothing wrong with it. My theories are now that a bad earth, maybe on the door connector overloaded a capacitor or resistor in the circuit or maybe the coils have failed. I did consider the contact breakers having a build up of carbon with it arcing but then I think it would have intermittently worked. I may consider going over with the multimeter but it is alot of grief.

If the problem reoccurs there must be a better option to either buying a new one from BMWԚ£70 or buying a second hand one from ebay which might not work. I heard on a land rover site about Hal frauds do a central locking kit for Ԛ£20. Maybe you could just use the module.

[Jos]

Keep in mind if you are looking for a bad earth you need to be doing it at 12V or more, the test meter voltage might not be might enough to show the fault. Very common in electrical mains testing (which is done at 500) for a multimeter to show open circuit then for it to short when you whack 230V across it.

[Brianmoooore]

Keep in mind if you are looking for a bad earth you need to be doing it at 12V or more, the test meter voltage might not be might enough to show the fault. Very common in electrical mains testing (which is done at 500) for a multimeter to show open circuit then for it to short when you whack 230V across it.

Hope you're not suggesting using a megger on E30 electrics. If the lock ECU wasn't faulty before, it will be afterwards, along woith a few other modules.

[Brianmoooore]

I
Reading through the forum I notice so many referrd to the module being the route of the problem and as I had my tourer sitting to be cannibalised I thought I would just try a different module as I knew for sure this one worked. And it did. No problems although I did notice a strange beep when I locked the car which has never happened before. It only beeped for four times but it seems to have stopped now whatever it was.

I took the old module apart but I can still see nothing wrong with it. My theories are now that a bad earth, maybe on the door connector overloaded a capacitor or resistor in the circuit or maybe the coils have failed. I did consider the contact breakers having a build up of carbon with it arcing but then I think it would have intermittently worked. I may consider going over with the multimeter but it is alot of grief.

If the problem reoccurs there must be a better option to either buying a new one from BMWԚ£70 or buying a second hand one from ebay which might not work. I heard on a land rover site about Hal frauds do a central locking kit for Ԛ£20. Maybe you could just use the module.

E30 locking ECUs are very reliable, unless they've succumbed to water damage, and all E30s have one, so they're not rare. There shouldn't be any problem in buying a second hand one from a scrappy. Just check that there are no signs of water damage, and the thermal trip hasn't been bodged.
Your problem is(was) nothing to do with earths. Unusual, but the module could just have failed. Irt contains semiconductor devices which look just the same faulty as they do when working, and can easily succombe to some electrical spike.

[telski789]

i have four!

[bmwe30mtech]

Probably the wrong place to say this but my locking is broken as well, its the drivers door lock, turns but doesnt lock, so this throws the whole system (except boot) from working.

Paul

[Brianmoooore]

Probably the wrong place to say this but my locking is broken as well, its the drivers door lock, turns but doesnt lock, so this throws the whole system (except boot) from working.

Paul

take out the lock barrel assembly(door card off and slide big clip to left with a long screwdriver). There is a lever on the end of the assembly that should toggle from side to side on an overcentre spring. It often seizes up.

[orkboss]

E30 locking ECUs are very reliable, unless they've succumbed to water damage, and all E30s have one, so they're not rare. There shouldn't be any problem in buying a second hand one from a scrappy. Just check that there are no signs of water damage, and the thermal trip hasn't been bodged.
Your problem is(was) nothing to do with earths. Unusual, but the module could just have failed. Irt contains semiconductor devices which look just the same faulty as they do when working, and can easily succombe to some electrical spike.

This might have been the case. My central locking was working although it did have the habbit of locking itself. I left the car standing for six months, had to change battery and heard the central locking clicking about. Then trying to lock it no central locking.

[dippae30]

...I was told that my 91 E30 didnt have central locking as it was a 316i..

thanks to this religous site i do have central locking after changing the module, also finding out that my sunroof drain pipe was spilling slightly into the cabin....one to make sure when down in the footwells...