Central locking failure...........need some help please

[peachers]

Hi,

Went out to use my 316i touring today after it had not been used for a week or so. It had been cold overnight and snowed a bit so was dubious that it would even start. I unlocked the car from the driver's door as normal but only the driver's door unlocked (I thought this was a bit strange as the central locking normally works fine).

It now appears that the central locking has completely packed up as all the doors are locked apart from the drivers door and will not open with the key or from inside the car (I think the doors may be deadlocked). The boot will unlock/lock fine with the key but the driver's door will not lock at all now!! When I try to lock it I can hear a groaning noise but the drivers door pin will not go down and the door will not lock.

Does it sound like the central locking pump has failed (if there is one??)/ the lock is knackered or will I need to perform the red/black fix that I have read about?

Any help would be greatly appreciated as the driver's door will not lock at the moment so the car can't be used.

Cheers,

Peter

[Brianmoooore]

The red/black fix should be performed on all E30's whether the locking is still working or not, but the deadlocking of all the other doors is a little worrying, unless you deadlocked it the last time things worked.
Dig the central locking ECU out from its hiding place inside the sill under the driver's foot well speaker, check it out for water damage, and check for permanent 12 volts at the red/black wire at the ECU's connector.

[peachers]

Thanks Brian,

Only just got a chance to have a look at this the other day due to the rubbish weather and because it has been busy at work. Thought I would try a quick fix first and replaced the central locking ecu with another that I had which funnily enough didn't make any difference. Whilst replacing the ecu I noticed that the red/black wire connected to it had green corrosion around the connector which may mean it has been water damaged? What is the best way to check that it has 12 volts running to it - is it to connect a bulb to the wire (apologies for the question but am a bit of a numpty when it comes to car mechanics/electrics)?

[Brianmoooore]

Connect a 12 volt bulb between the red/black wire and the brown wire at the locking ECU's socket to check for power.
Green corrosion isn't good, but doesn't necessarily mean water has got inside the unit. It's easy to open and check.