Hi all, I've had an intermittant issue with the drivers door on my (RHD) 2009 Fabia3 1.9TDi, where it thinks the front door is open, when it isnt. It's quite an intermittant fault, but can happen and then rectify itself several times on a journey.

 

I've done some searching through the forum which seems to suggest the likely culprits are either damaged wiring in the bellows where it goes into the door, the lock microswitch, or the electric window motor (which I understand is the control module, or something like that for the lock).

 

I'm going to take the door card off this weekend and try fault find, but can anyone advise on part numbers?

 

I'm finding it all a bit confusing, as according to the info on skoda.7zap.com there seemed to be a change in part numbers in 2009. With a different part number for cars up to 06.12.2009 and another for cars after 07.12.2009. As mine was registered in June 2009, I'd like to assume that means I'd fall into the first category.

 

I think the lock is 3B2 837 016 AB, as cars from 07.12.2009 would be part 5J2 837 016.

Then with the window motor 6Q1959801G (as that was 05.11.2007 - 30.08.2009).

 

Does that make any sense whatsoever, or am I being a total numpty?

 

Thanks.

 

Can be a faulty connection between the door and pillar hinge side, some times the connection gets corroded and causes all sorts of issues, try this first before anything else, the best way to get at it is take the door stay off--remove the bolts so the door can open wider than normal pull back the rubber cover then unclip the connector and give it a good clean with WD40, when i did mine  and then  put some  petroleum jelly on the socket end and plug end before clipping them back together, my issue was the door not locking correctly and this sorted the problem out for me

I think you're correct about lock part numbers.

 

I don't think the window motor unit will have any relevance. I don't think the lock wiring even connects to it? Will check later when I get on a big screen.

 

Edit: One or two wires from the lock do go there, but in my experience the problems are usually at the lock unit itself (on mk1s), and/or on mk2s the door bellows are a dodgy design so always the first place to look. 

Edited 19 February, 20215 yr by Wino

Thanks to you both, very much appreciated. I'll check the connectors and give them a spray with some electrical contact cleaner. If this doesnt sort it, I'll have to try and source a new lock, I wonder if the breakers near me is open.

 

Thanks for clariying about the window motor Wino, I wont waste my time faffing about with it.

Just a quick update. Had the door card off today, checked all the connections for corrosion, then cleaned with electrical contact cleaner.

Checked the door bellows, no obvious damage, so as above, checked connector blocks for corrosion, then cleaned.

I then put everything back together again, lock the car, start walking in the house, and the bloody alarm starts going off... FML! Microswitch it is I suppose. Now to source a replacement lock.

Before trying to change the microswitch, reflow the solder joints in the electrical module attached to the lock. The 3B part number means that lock was originally designed for the B5 Passat, a car well known for dry solder joints in the locks.

A little example of such a broken joint. I think it's a mechanical wear and tear thing with years of door shutting and consequent flapping of the loom near the connector.

This one wasn't easy to spot initially because of the conformal coating painted over the solder joints:

 

Thanks chimaera, I'll have a mooch around the interwebs and see if anyone has made a helpful video.

 

Edit: sorry wino didn't spot your post. Thanks for all the helpm

Edited 21 February, 20215 yr by swedeytodd
Missed a post answering the question

This was a passenger side module on our mk1. Tkae lots of photos as you go along if you do decide on dismantling for a look; will probably help reassembly.

Had the door card off earlier, I was correct re: the part number. Though after speaking to some parts suppliers a brand new replacement lock is about 115quid, so I've elected to get a second hand one off ebay. A risk I know, but for 20quid it's worth a punt. Hopefully arrive before the weekend.

Thanks again.

On 23/02/2021 at 14:15, swedeytodd said:

Had the door card off earlier, I was correct re: the part number. Though after speaking to some parts suppliers a brand new replacement lock is about 115quid, so I've elected to get a second hand one off ebay. A risk I know, but for 20quid it's worth a punt. Hopefully arrive before the weekend.

Thanks again.

How did you get on with this?

 

I currently have the same issue with a 2009 Fabia and looking at the same things for a solution (so far its not bellow wiring, not microswitch, not dry solder joints or drivers side).

While I was waiting for the ebay lock,  it seems to have rectified itself, which is a pain. I suspect its weather/humidity related. Mate of mine has a similar problem in his old audi in hot weather and that what he's convinced it is.

 

Annoyingly the passenger side has now decided to not open at all, either from inside or out. Anyone know what fuse controls the central locking? I think I need to pull it to free the lock.

Thanks for the update. In the meantime I did manage to solve the same problem with mine by reflowing the solder joints in the window control module: