Passenger Side Door Lock Fault

[Ting]

Hi all,

Since an accident before Christmas (due to the bad weather), my passenger side door has been playing up. It was replaced with the garage who did the work and everything seemed fine at first. But a month after that it started acting up..

Basically; if I lock the car using the key fob its alright, but if I press the interior button to lock it, it locks but then instantly unlocks a second later almost every time (only the passenger door unlocks)

Also, if I try pressing lock on the key fob twice it should just keep it locked right? well it keeps all the other doors locked except the passenger one, which unlocks. but it does lock with only one press of the lock button

It feels like, in some way its an electrical fault rather than mechanical, because sometimes it DOES lock but other times it only locks with the key.. it might just be me, but it also seems like it only does it when its been raining (not 100% on this) so I thought possibly something is shorting in the wet?

Other than that some people have said it could be something to do with a fuse, or the sensor for the door thinks the door is still open.. but theres nothing obvious mechanically because I've had the door card off already and everythings connected etc.

Any help is much appreciated! And thanks for actually reading this far lol


Cheers, Martin

 

[Ting]

Anyone? Even if its not that helpful just any info is at least something..

I've even spoken to my local mechanic who is a good family friend who can't say for definite what it could be.. He's gonna look at it next week for me though so hopefully he finds something.

 

[Neo]

Hi Martin!

Now I`m no expert but it sounds like your N/S lock module is giving up on life!
Problem is they are a right pain to get to as you need to remove both the plastic door card and the metal inner one to get access to it:

Not sure what they cost new but there are some on ebay... however a second-hand one is`nt guaranteed to work as I found out!

Not sure if you are thinking of fixing the fault yourself?
I recently fixed my door-lock microswitch (part of this module), so I can offer help on removing the cards etc if you want... it was on the driver`s side but it should be more or less the same.
I took pictures so I may do a guide soon too.

EDIT: just noticed you said you had the door cards off! hope it helps anyway!

 

[thePHILosipher]

i had i near identical thing:

• Click to lock car
• double click lock to deactivate interior sensor
• passenger door then unlocks

i had the wiring checked and it was found to be a dodgy latch that was replaced and its been fine ever since

 

[Ting]

Thanks a lot Neo and Phil!

I have actually replaced one of these lock modules before, but on the drivers door - some how the glass fell out of the holders for for the electric windows so had get a whole new runner system for the windows, and had to take the it apart, including the lock..

I think i'll check the latch to see if it was correctly fitted etc because I remember the drivers door one being a bit fiddly trying to make sure everything is in place before bolting it back up.

I'll let you know how I get on to help anyone else who comes across this in the future..

 

[Keir]

If you don't lock the doors yourself and just drive, do the doors auto lock? (passenger side stays locked)

 

[Ting]

All doors auto lock but then the faulty door (front passenger) unlocks a second later..

 

[Slimy]

Strangely enough, my Toledo does EXACTLY the same thing! It'll lock fine off the remote, but locking via the drivers door switch has the passenger door opening a second later, as did the anti-hijack locking. That got really irritating when driving, as it did it every time I went above 15 mph. The other doors just stayed locked.

I have to press the remote button three times to get the alarm to beep, it used to take only one press. I'm guessing it's once to lock, twice for the interior sensor, then a third to get the alarm to arm properly.

Philharris, what do you mean by a dodgy latch? Did you have to replace the entire lock module as in Neo's photo, or as there a smaller part that could be replaced?

 

[thePHILosipher]

i believe they replaced the whole module like neo said, mine was done under warrenty so i dont have the finer details.

The details on the sheet provided by the dealer states

'investigate in to passenger door faulty checked all wiring all OK, stripped down passenger door panel and replaced door latch, put back together all OK'

 

[Neo]

Thanks a lot Neo and Phil!

I have actually replaced one of these lock modules before, but on the drivers door - some how the glass fell out of the holders for for the electric windows so had get a whole new runner system for the windows, and had to take the it apart, including the lock..

I think i'll check the latch to see if it was correctly fitted etc because I remember the drivers door one being a bit fiddly trying to make sure everything is in place before bolting it back up.

I'll let you know how I get on to help anyone else who comes across this in the future..

Ok mate, yes it`s a rediculously fiddly job!

I agree with your original post about it being an electrical issue though as it locks fine.. just unlocks a second after. This suggests the mechanical side is ok.
A common issue with the VAG modules (not sure how different they are), seems to be the soldered joints on the internal circuit board - the solder cracks making the associated circuit intermittent.
I was going to look for this on mine but I diagnosed my fault as the microswitch first.

 

[Ting]

Hmm.. Alright then, I'll try and get some enthusiasm from the old man to help me take the door apart and check it. He's an electrical engineer so would probably know what to look for, at least more than I would.

I really do think its something to do with the rain though because it was fine early today, then it started raining just before I had work. When I got in it to go to work the anti highjack went off locking the doors but then the passenger side unlocked a second later.. but then when I get out when I got to work, I press the lock on the fob and bingo it locks fine.

So strange..

 

[Ting]

Did a little search on Google and found this from a VAG site:

http://vagclubbrunei.blogspot.com/2009/12/mkiv-door-locks-explained.html

could be helpful later when I'm checking the lock module, so thought I'd share it.

 

[Neo]

Did a little search on Google and found this from a VAG site:

http://vagclubbrunei.blogspot.com/2009/12/mkiv-door-locks-explained.html

could be helpful later when I'm checking the lock module, so thought I'd share it.

Good find! It refers to the solder problem I mentioned. And the metal door card seems to be identical to the mk4 ibiza too!

Although I can`t see how the solder issue is affected by water? Strange

 

[Slimy]

Good find! It refers to the solder problem I mentioned. And the metal door card seems to be identical to the mk4 ibiza too!

Although I can`t see how the solder issue is affected by water? Strange

Actually, I think I know why. My back door window switch went on the blink sometime before I got the car. I got round to looking at it last weekend, it looked like the contacts had gone green and wouldn't connect. Unfortunately cleaning them up didn't make any difference.

However, when I opened it up, I noticed the green copper corrosion had actually lifted a contact off one of the tracks, and broke the connection. A simple solder job later, and I had a working switch again!

The only water that could have got to the window switch is condensation from inside the doors, and it's quite likely the same water that could be in the door lock. And if it managed to lift a track inside a switch, it could quite easily do the same in the lock.

Coincidentally enough, I came home tonight in pouring rain, and my door lock actually started working! Of course, as soon as it dried out, it went back to normal...