Technical Central Locking, car thinks a door is open but it's not?

[Manic mechanic]

Hi all, this is now my second post on here, so if you've seen the other apologies for repeating myself. Our car was in an accident, hit by another car on the drivers door and front wing. Since this time we have had issues with 2 things, the central locking and window mechanism, see separate post.
So when we lock the doors using the key it appears to think there is a door ajar and immediately re-opens all the doors. We have changed the handle, which was lightly damaged in the accident, checked wiring and all connections and swapped the locking mechanism in the drivers door but nothing has made any difference. I am thinking there must be a "Locking Module" but not sure where it is? Currently we have just removed the Central Locking fuse and we just lock'unlock manually which is fine (bit of a step back in time). With the main impact being the drivers side wing, door less so I would of thought it woiuld be something in that area but I don't see anything inside the door, anyone clarify?

 

[bugsymike]

When you mention swapping the locking mechanism in the drivers door do you mean the catch part in the end of the door that engages in the door frame of the car?
If so have you tried with the door open, manually using a screwdriver or similar to push the catch in the end of the door, it should have two definite positions, so push it to the second position as though the door was fully closed and then see if the door lock will operate the central locking.
If it does then the door is out of line when shut, not fully shut, or the catch is not recognising the fully closed position, I assume all this happened due to the accident.
After doing this test release the door catch by the handle to prevent damage when closing the door as already in shut position.

 

[Manic mechanic]

Yes the catch part as you say and yes we have tried moving it manually but it just pings back open. IOt seems to be from the accident but as far as the door isconcerned it was really just a light impact on the handle and a dent about 10" across before it went into the wing, which was pretty mangled. The edge if the door was bent and needed pulled back out but the panel gaps frontand backare really OK.

 

[bugsymike]

Yes the catch part as you say and yes we have tried moving it manually but it just pings back open. IOt seems to be from the accident but as far as the door isconcerned it was really just a light impact on the handle and a dent about 10" across before it went into the wing, which was pretty mangled. The edge if the door was bent and needed pulled back out but the panel gaps frontand backare really OK.

When you say it pings back open, how does that compare with passenger door?

 

[Manic mechanic]

Exactly the same, lock it and it immediately unlocks. Also, should have said this earlier, the 'door open light' is on, on the dash, even when allteh doors are closed.

 

[bugsymike]

Side and back doors also?

 

[Manic mechanic]

Yes all the same.

 

[bugsymike]

So one of the doors still thinks it's open, is this only since the accident?

 

[The Panda Nut]

We have a Seat Leon which played up like this. Inside the locks are tiny micro switches which signal door open and closed as well as having lock and unlock functions. One switch wore out. This involved wearing aboyt 1/5 mm of rubber off the switch. Replacing it with non Seat swich did not work. Only an original replacement loxk cured it. Does the interior iight work normally? This was also affected on ours. The components and wiring were so small the tiniest misalignment made a big difference. As soonas a new seat lock was fitted it was ok again. With only one door with a key hole it meant that lock was a master loc⁶k.

Had a similar issue with Panda boot lock. Liberal use of silicon spray and cleaning the handle pivots cured this allowing handle to return to correct position. 1/3 mm difference was all that was needed to prevent it working.

Look at the other locks too. Check child locks are fully off or on on the rear doors too.

 

[Manic mechanic]

Bugsymike, Yes just since the accident.
The Panda Nut; That's interesting, plenty information there, only thing I think is that Fiats are less technical than VAG cars but you never know it might just be the same. We have a guy who is a really good locksmith nearby but he's incredibly busy and hard to get hold of, I might try and get hold of him and see if he can confirm. I am really not sure about teh interior light, can see the significance of this but it's always been daylight when we have been wprking on it, for obvious reasons, will check though. Right npw the central locking fuse is pulled and we are just driving it and using it manually. Thanks for your reply.

 

[AndyRKett]

In the locks (latch inside the door) there is a "door Ajar sensor" as stated above its a tiny micro switch. Sounds like yours is broken. quite common when these get damaged that the car keeps popping the locks back open thinking the door isn't shut properly.

Not something a lock smith has to deal with. It is simply a case of replacing the latch inside the door.... usually.

If you're 100% sure the lock is ok and its a car that has been in an accident, then either the wiring is damaged or the catch needs adjustment to get it to correctly sense the closed door

 

[Manic mechanic]

Bugsymike asked about interior lights, checked today and none are coming on with the door opening, we just hadn't noticed, it's getting darker earlier but still quite light in the evenings, so didn't notice. What we did notice was that when you open/close the door the dash panel with the mileage etc lights up and goes off as it should. So it knows when the door is being opened and closed but the rest of the car doen't seem to, which might be significant in some way.
We swapped the door handle, couldn't see any wires going to the handle, so thinking how would a micro-switch work or maybe it isn't in the lock in a Doblo? Anyway it was no different with the other handle, so now back to the original.
AnydyRKetts points above; we did swap the door latch for another 2nd hand one in the past and it again didn't make any difference. I don't think the door was damaged enough to damage any wiring, as I said above it was just a shallow dent about 10" across at the front of the door and the wing took the brunt of the impact. I have now repaired the damage to the door and wing and the allignment is good as are the panel gaps but that's not to say that something is out of allignment, that allows the car to know the dooris open/closed.
We did a bit of re-setting the light on the dash by disconnecting the battery and checking each of the doors and as far as we could ascertain it is recognising the back doors, passenger door but not the drivers or sliding doors, again that may be significant.
Would a diagnostic scan throw up anything, I don't have a scanner compatible with the Doblo but maybe I should or maybe I shouild just find someone who does and see if they will scan it on the cheap?
Appreciating all the comments and information, so keep them coming!

 

[The Panda Nut]

We ask about the lights as if the door latch is not fully clicking over to its closed position the interior light would come on. If there are no interir lights is this just because the light is actually switched off. If its set to switch on when the doors open it may be part of the problem. If the car has central locking it must have wires attached to the lock. These will be on the lock its self inside the door. A short circuit to earth of the door lock wiring could cause this faut and bear in mind it might no be hte damaged door casing the fault. Open all the doors and then use a screw driver to turn the lock latch to clused on all the doors and the tailgate. Undo each door latch by pulling the handle and see if this rules out any or all of the doors from being at fault. With the doors open you can try each lock to check the y doo all activate the dash light and hopefully confirm which corner / door is involved.

 

[Manic mechanic]

OK, on the last one I will give that a try, it's similar to what we have done before but I think worth doing as a separate process, thanks for that.
We have been manually closing the latches on some of the doors, just so we can keep the door open while testing that the car knows whether the door is open or not. So manually closing the latch to the second position should tell the car the door is closed but it doesn't with the drivers door anyway.
I don't see any wires to the lock barrel or the handle it'sself but I have seen central locking solenoids for sale for these cars and I assume they are attached to the mechanism and operate the locks from there?

 

[Manic mechanic]

Sorry I haven't been on for a wee while, just catching up with my E.Mails and loads of Fiat Forum links. I did try the test bove but it wasn't greatly helpful. Ibelieve the interior lights are switched on to come on with the doors, I certainly remember asking my Wife to check she hadn't switched them off, so they were on when we were messing about with it. The problem is none of the rear doors (sliding and back doors) seem to be getting monittored by the car. So only the 2 front doors put the light on and then it's stuck on intil you pull the fuse or disconnect the battery. So I'm thinking maybe a wiring diagram might be of help, to see if the path of the wires would allow the front doors to be on and the rest permanently off. We managed to speak to our Locks guy and he seemed to think it was worth him having a look at but he is very busy and we haven't managed to pin him down to a date yet.

 

[Manic mechanic]

Hi guys, apologies again but thought I should get back on here to tell the end of the tale.
To cut a long story short we weren't getting anywhere with it so my Wife decied to take it to an auto electrician we have used in the past, usual thing, not cheap but pretty good at what they do. So they fixed it but as she picked the car up I wasn't able to ask exactly what they did. According to her they found a broken wire dis-connected from the OBD port. This was a live wire and explains why my scanner I connected up didn't power up, not because it wasn't compatible with Fiats, in fact it seems it is compatible, so should be able to scan for fault codes in the future. Why this live was broken and why it had such am inpact on the central locking and apparently little else I am unclear, sounds like it was maybe damaged already before the accident and the shock through the vehicle was the final straw? who knows.
Sorry it's a kind of unsatisfactory conclusion but if anyone can make sense of this, I would be interested. Thanks again for all the help and info you all gave, much appreciated

 

[The Panda Nut]

Hi guys, apologies again but thought I should get back on here to tell the end of the tale.
To cut a long story short we weren't getting anywhere with it so my Wife decied to take it to an auto electrician we have used in the past, usual thing, not cheap but pretty good at what they do. So they fixed it but as she picked the car up I wasn't able to ask exactly what they did. According to her they found a broken wire dis-connected from the OBD port. This was a live wire and explains why my scanner I connected up didn't power up, not because it wasn't compatible with Fiats, in fact it seems it is compatible, so should be able to scan for fault codes in the future. Why this live was broken and why it had such am inpact on the central locking and apparently little else I am unclear, sounds like it was maybe damaged already before the accident and the shock through the vehicle was the final straw? who knows.
Sorry it's a kind of unsatisfactory conclusion but if anyone can make sense of this, I would be interested. Thanks again for all the help and info you all gave, much appreciated

Thanks for telling us the end of the tale. My experience of CAN bus wiring is it got a mind of its own and you cant always trust what the warnings say. Its always useful to know what the cause was as it might just help someone else. Im glad you got it sorted.

 

[bugsymike]

At least problem solved.
I had a problem I spent ages on and in the end two hours labour at a specialist diagnostic sorted it out, cross with myself as should have found it, but job sorted so what can you say.

 

[Morry1944]

Hi, I am glad you got your problem solved but I have exactly the same problem which appeared out of the blue. The car thinks one of the rear sliding doors is open when it isnt. Consequently when you try to lock the car it immediately unlocks again. The door warning light on the dash stays illuminated and the message displays rear doors open. Referring to the sliding doors, not the actual rear van door. (2009 Doblo MPV Multijet 1.9D).
Ive checked the 4 pin connectors to the doors and removed them and checked the black plastic normally Closed switch which the sliding door actuates and all seems to be correct. This would have been an easy fix, but it wasnt that. Did you get any more information on which wire was faulty with your problem as this has got me puzzled and I normally solve electrical problems but these Fiat Doblos seem fault ridden.
Morry