Golf Mk4 locking problems

[vicegrip]

Golf Mk4 2003 - just bought a week ago:

1) No problem noticed with locking in first week.

2) Yesterday, person with plug in diagnostic tool noted that it was indicating a fault with the drivers door - and said that if door was behaving OK it probably didn't matter.

3) (Today) Car did not seem to recognise that the driver had entered and was sitting in the seat. The doors all locked automatically after about a minute, the alarm went off and the door switch for unlocking didn't work.

4) There is also an issue with the boot catch (its a hatchback) - the car is inclined to beep and warn that the boot is open as it is being driven. Is this something needing adjustment, or could it be related?

Is this problem familiar to anyone? Looking on Ebay I see "VW Golf Mk4 Front Right/Driver Side Door Lock Control Unit Mechanism (1997-2005)" for about £50. Is this a likely culprit/fix? If so, is fitting straightforward? Does it need to be matched to the key?

[Flash2]

Your tailgate warning could be a faulty switch in the latch. They are usually damaged by water ingress when the rear washer hose comes off the wiper motor. I'd also take a look at the wiring in the loom between the car body and the tailgate. It routes through a rubber tubing near the N/S tailgate hinge and can be damage by the flexing of the loom everytime the tailgate is lifted (see photo).

The door locking when you entered the car isn't a fault. When you unlock the doors and don't turn on the ignition, the doors will re-lock again and the alarm will arm. I've seen a few folk have their keys locked in the car because of that...be careful.

Jim.

[vicegrip]

Thanks for the quick reply - and excellent photo re the tailgate.

Are you sure about the auto-locking? If it is meant to work like that, it is different from the Passat - have just tried Passat (TDI estate 2001) and find:

1) If I unlock it with key-remote and do nothing it auto-locks after about 30s.
2) If I unlock with key-remote and get in, without inserting key it doesn't auto-lock.
3) If I unlock with key-remote and just open and shut either drivers door or the rear right door that also seems to cancel auto-lock.

If there is not a fault then that is good news - am a bit trigger happy about faults at the moment.

[Rowsi]

I am new to this too, if you open the car door physically, do the interior lights turn on? does the door paddle light come on, if your lights are on does the buzzer sound. If yes the door seems to be fine. There is loads on Google about this. I had a rear door problem too, but in the end it was just the barrel not turning fully to vertical so the central locking did not work. I am going to strip my drivers door down sometime to clean the micro switch as my door thinks it is closed all the time and the above list of three does not work. Not a big deal but one day I will leave the lights on.

[Flash2]

Thanks for the quick reply - and excellent photo re the tailgate.

Are you sure about the auto-locking? If it is meant to work like that, it is different from the Passat - have just tried Passat (TDI estate 2001) and find:

1) If I unlock it with key-remote and do nothing it auto-locks after about 30s.
2) If I unlock with key-remote and get in, without inserting key it doesn't auto-lock.
3) If I unlock with key-remote and just open and shut either drivers door or the rear right door that also seems to cancel auto-lock.

If there is not a fault then that is good news - am a bit trigger happy about faults at the moment.

Maybe your right and opening the door cancels the autolock feature and not turning the ignition like I thought.

If that's the case then I'd check what Rowsi suggests. See if the lights on buzzer works when you open the drivers door. If not, then the autolock was activated because the control unit isn't getting the signal that the door was opened.

Jim.

[vicegrip]

I am new to this too, if you open the car door physically, do the interior lights turn on? does the door paddle light come on, if your lights are on does the buzzer sound. If yes the door seems to be fine. There is loads on Google about this. I had a rear door problem too, but in the end it was just the barrel not turning fully to vertical so the central locking did not work. I am going to strip my drivers door down sometime to clean the micro switch as my door thinks it is closed all the time and the above list of three does not work. Not a big deal but one day I will leave the lights on.

Thankyou for these tests - it does look like there is a fault:
When the passenger door is opened, the interior light comes on, but not with the drivers door.
Door paddle light ? if this is the little illuminated warning that a door is open - no - not working.
If the lights are left on and the door opened, the buzzer doesn't sound. Daughter pointed this out when buying the car, thinking it was just the car and dealer laughed it off

So what does this lot point to?

[Rowsi]

OK Sounds the same as mine, if it is the same as mine it is probably the micro switch in the door lock system that needs a clean or replace the whole lot. In UK Ebay they seem to go for about 30quid new. One day soon I am going to try to repair mine, not to save the 30Quid but just to see if I can. But living on the West Coast of Ireland I need a nice sunny day to do it....

VW Door Lock Control Module Fix Repair, Simple Easy Repair - YouTube

this is the one, two videos to watch to get to this.. But the bit at 7 minutes is my problem

[vicegrip]

OK - just watched it - and he says the micro switch is a very common fault, so sounds right. Good video, thanks. (If I tried that I'd want to test micro switch was working using a multimeter and a couple of test leads connecting to safety pins stuck into each wire.) The electrical cleaner aerosol looks useful - is new to me.

Perhaps the rear door has a problem as well - it has a slight dint in it - if I was cynical I'd think it was where the dealer whacked it do a temporary fix!

[Flash2]

For the sake of £30 and taking into account the work involved in removing the door lock, I'd just replace the whole assembly. Having said that, I know the original VW part is about £130, so I wonder if the e'bay pattern parts are of the same quality? I wouldn't fancy having to strip all the door down again after a few weeks if the cheap copy part failed, not to mention trying to convince the e'bay vendor to replace it under warranty.

The other option is to buy a replacement micro switch. The original switch, I'm pretty sure, is a Burgess V4N.

Burgess : V4NSUL | SPDT-NO/NC Plunger Microswitch, 3 A@ 250 V ac | Saia-Burgess

Equivalent : http://www.rapidonline.com/electroni...-lever-78-0865

Jim.

[vicegrip]

Definitely. And more so in this case as it is my daughters car and a few hundred miles away and she is not the DIY type (to say the least). I think the cheap Ebay stuff is often OEM. Have just seen two units for £40 - from Germany. In this case the dealer should be coughing up under guarantee but not sure if it wise to let him get his hands on it. Thanks for the microswitch links.