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Discussion Starter #1
Hi guys

Looked around on many threads and can’t seem to find an answer to my issue.

I am having lock issues and tried the usual checks:

Checked wiring loom under drivers seat
Removed battery to reset the bcu
Unplugged bcu while car turned on.

Issue I am experiencing is as follows:

Neither doors unlock with remote key or switch on drivers doors (tail gate and side door do). The only way of unlocking the drivers door is by putting key in lock. Only way of opening passenger door is using internal handle.

The passenger door does sound like it is trying to unlock / lock as it slightly moves the lock pillar / indicator but only occasionally.

In addition when the alarm is activated the lights flash but no sound is made.

Any suggestions as to next steps.

Cheers
 

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Only way of opening passenger door is using internal handle.

The passenger door does sound like it is trying to unlock / lock as it slightly moves the lock pillar / indicator but only occasionally.
I would advise that you go to a VW commercial dealer and buy a passenger side lock, and replace it immediately. Because at the moment it is failing to deadlock - if it does succeed in deadlocking and then jams again you will find that you can't open it with the inside handle, and then you have a horrible job on your hands...
 

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Could it be the actuator in the door have failed or the bcm? Have you checked on VCDS for a fault code as you can check what the doors are doing.
 

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There is only one maker of VCDS - Ross-Tech. They have several UK agents, and it's best to have a look at current prices for all of them, because sometimes one will have a promotion on with a slightly lower price or some extras thrown in.
 

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If you're feeling brave, I found it was really useful to test each door lock by applying +/-12V (e.g. a small lead-acid battery) to the motor pins at the CCM connectors. You need a wiring diagram to work out which pins, but essentially 'blipping' each motor with 12V will either lock or unlock (depending on polarity - do both to check everything works). Each one needs two 'blips': one to lock, then a second to deadlock, and another two blips to unlock.

I found with mine that the locks/actuators were all fine, but the relays in the CCM weren't quite closing - they clicked but didn't actually pass any current. Once I'd replaced the relays everything was fine, but it was very difficult to diagnose!

HTH,
Rob.
 

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I found with mine that the locks/actuators were all fine, but the relays in the CCM weren't quite closing - they clicked but didn't actually pass any current.
Were the actual door locks making a noise as though they were trying to lock though?

This is what the OP reports, at least for the passenger door.
 

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Were the actual door locks making a noise as though they were trying to lock though?

This is what the OP reports, at least for the passenger door.
Yes, the OP's symptoms are quite like mine were: occasional signs of life, clicking etc, but nothing consistent and some locks did nothing at all. It's conceivable that the relay contacts would occasionally close with low resistance, and at other times a bit higher - enough to make the motor click but not enough to drive the mechanism.
 

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Probably easiest to change the CCM for a secondhand one for most people. Changing soldered-in relays is not the easiest of jobs, unless you're used to doing that sort of work!
 

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Probably easiest to change the CCM for a secondhand one for most people. Changing soldered-in relays is not the easiest of jobs, unless you're used to doing that sort of work!
Yes, of course. Really only suggested it for those on a budget and who are moderately handy with a soldering iron. And also as a diagnostic method to help decide whether or not to try a new CCM.
 

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I have replaced the CCM but unfortunately this has not helped. Anyone got a wiring diagram for the locks so I can check if they are getting 12v?
I found the diagram in the Haynes manual was mostly right (though quite difficult to follow). I've got some notes at home too - if I can find them I'll type them up here.
 

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On my van (2007 T5 1.9 barn doors, no electric windows), the CCM has two connectors fitted, a big 23-pin one and a smaller 12-pin one. There's space for a third 12-pin one which isn't connected.

On the big one, the actuator connections are:
#18 and #20 - rear (barn) doors
#19 and #21 - passenger (front left) door
#1 and #22 - driver (front right) door

On the small one:
#10 and #12 - left side sliding door
(possibly #9 and #11 is right side sliding door?)

If your CCM is different, stop now - I probably can't help you.

Unplug the cables and measure across each pair above on the cable side (not the CCM) with a good multimeter. You're essentially measuring the motor winding in each lock, and are looking for a very low but not quite zero resistance, e.g. a few ohms IIRC.

If you succeed in finding low-but-not-zero resistances, you could then try blipping each pair with 12V from a small battery, e.g. from a motorbike or similar. You should hear each lock make a noise, and hopefully even get them locking and unlocking. Remember, two blips (<0.5sec per blip) to lock, swap the + and - over, and two blips again to unlock.

If all the motors and locks are working ok, then the next thing to check is the microswitches. That's most easily done using VCDS, but I have wiring details if you want to try the hard way. :)

Good luck,
Rob.
 
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