[SOLVED] Audi S8 2002 - Can't unlock using key
 

Hi guys,

This issue is puzzling/concerning me. Has anyone come across this before or get any ideas what the cause may be? ...


My car is an Audi S8 2002 (Final Edition, D2).


Problem: I can lock but not unlock the car using a key, from either the driver's door or the boot/trunk.
(regardless of whether the car was locked using a key or a fob)


Things I've checked:

• Lock and unlock using the Remote key fobs works.
• Lock and unlock using the internal door switch works.

Which initially led me to think the problem must be a faulty door lock switch, but here's the strange thing ...

• When attempting to unlock the door with the key, even though the car doesn't unlock, the interior lights come on.
• And even stranger; if the ignition is switched on, using another key, the car can be locked and unlocked using a key in the driver's door.

Now I recently coded a few more key fobs, using VAG COM (which worked fine), but I've never really had the need to unlock the doors using the key, so I don't know whether it's something I've screwed up with VAG COM or whether it's always been like this. Either way, it concerns me that if there were a problem with the remote key fobs in future, I would have no way to unlock the car.


Any help/suggestions would be much appreciated :)

Interesting.

I was 99% sure that the key unlock in the drivers door, and boot for that matter are entirely mechanical. They are designed to operate with a flat battery, so, if the key fits, and turns, it should open regardless....:Confused:

Once the door is opened, you have to put the key, with the immobilser chip in the ignition within 15 seconds to disable the alarm from going off.

This is the whole design of the small black wallet key.....

Its interesting that you can lock, but not unlock. I didnt think the D2 had any sort of deadlocks, so maybe there has been some sort of physical damage to the lock ?

With power, when you turn the key in the lock, it makes contact which then activates the central locking pump, interior lights etc. If the electrical contact for 'unlock' was broken, I could see how only the drivers door would unlock and nothing else when you used the key, but I cant understand how the mechanical lifter wont lift.....

Thanks very much for the reply :)

Yeah, that's what puzzled me too.

I owned 2 A8s prior to this (a '96 and a '97 model) and I'm sure the driver's door locks operated mechanically on those. Whereas this late 2002 D2 S8 (one of the very last D2s I believe) is almost certainly not mechanically operating the lock. It 'feels' purely switch-like ... very little mechanical resistance as you turn it, other than the spring-back tension.

I was of the understanding that it does have deadlocks though. I'd have to check to confirm, but I'm pretty sure the deadlocking features are mentioned in the vehicle's owner's manual. Also, you have to double-pull on the internal handles to get out when the doors are locked .... isn't that a deadlock thing?

The boot lock feels mechanical however, but that won't unlock the car either, only the boot itself.

Well mines a 2003-reg, very late (2002 built) D2 S8 and the door key is very mechanical. Suggests something broken in yours.....

No. 1 pull unlocks it, 2nd pull opens the door. If it were deadlocks, then by definition you wouldnt be able to open it from the inside at all..... +++

From what you describe, its almost like the contact for 'unlock' is electrically not making it back to the central locking pump in the boot, which controls all this stuff.

As a wild, wild guess (As wiring is generally reliable) I wonder if anyone has ever replaced the CLP (which often fail) with slightly the wrong one, coded it incorrectly or somehow messed with the wiring plug?

Welcome by the way, always nice to see new enthusiasts who are able to articulate a well constructed post +++

I don't recall the exact pattern when I had trouble with the locking on my last 2002 S8, but it was pretty similar. I could lock on the key in the door but not unlock, and I could unlock the boot with the key, but not the rest of the car.

It turned out to be 2 faults: first, the central locking pump had an intermittent failure; and second, there was a mecahnical link in the driver's door that was disconnected.

The latter had clearly been the result of a previous owner fiddling about behind the door card and not reconnecting the link, but I'd never noticed because I'd never tried to unlock the door with the key.

BTW, an introduction and photos of your car are essential if you want the stream of advice to continue! :D

Ah, of course. Doh!

But that's the puzzling thing ...

From an electrical point of view, the central locking ECU is clearly seeing the unlock contacts close/open because, with the ignition on, it unlocks the doors (which, I must say, I find bizarre!) and, without the ignition on, moving the key to the unlock position, turns on all the interior lighting.

Why thank you kind sir .... I do try :D

I have actually posted here before ... about 4 years ago in fact, when I first purchased this car, but my user account was closed (probably due to lack of use). I've purchased countless parts from you too over the 10+ years I've owned my various '8s. Actually, I might be looking for a used, complete S8 fuel tank soon, but that's another story/thread ...

Ah, brilliant, thanks for that.

In that case, maybe mine is presently working entirely electrically and whatever mechanical linkage there should be is missing, broken or fallen off. That would make sense I think.

I was kinda assuming I'd maybe screwed something up using VAG COM, but I'm guessing it probably wasn't working before that. Time to Study ElsaWin I think, see if I can see what might be missing/broken.

Ah, great thanks. :D

That further confirms it. Gotta be a mechanical linkage I reckon.

lol

I actually don't have many photos of it, but I will take some soon and post a proper intro. I've just spent over 3K on the car in fact, getting it back to showroom condition, so I think some photos are definitely required.

Here's one from a couple of years ago: http://i.imgur.com/2o2DSQ4.jpg

Just to add that when I unlock the drivers door with the key only that door unlocks and the interior lights come on. The other doors unlock when the ignition is turned on.
When locking with the key all doors lock and the alarm chirps.

I assume that unlocking behaviour is down to the settings I have, I've changed them a fair bit (noted in another thread) with VCDS.

Ok, thanks for confirming :)

Mine doesn't unlock any of the doors, so it sounds like that part at least should be mechanical. Looks like that's the missing link(age).

Ok, I think I found the relevant illustrations.

Before I strip the door down, I'm gonna take a guess that link rod #1 is missing or disconnected. Would y'all agree?

http://i.imgur.com/EbQwwp1.jpg



Same rod on this image is #10, I think ...

http://i.imgur.com/GUdBamg.jpg



Looks as though the door should pull that rod up/down.

Just for the record, my door lock is now fixed. :)

It was indeed rod #1 (in the first image above) that was disconnected.

It seems the door had been taken apart by a previous owner/garage and someone neglected to reconnect the linkage.


Interesting though how the electric-only operation behaves when there's no mechanical intervention, especially how the door can be locked (with the key) but not unlocked, unless the ignition has been switched on (with another key) ... bizarre.



Anyway, thanks for all the info and help guys :)

Pleased you got it sorted - just the same problem as mine a year or two ago.

Thanks.

Identical, I'd say ...
... including the bit about not noticing the problem.

If it wasn't for the new key programming procedure, I would probably have never thought to try unlocking the door with a key until it was too late!

Good to know I can now get back in the car should the remote be inoperable, for whatever reason.

Yes, I was in Stranraer (south west Scotland) on a Sunday when my central locking pump failed and I discovered I couldn't get into the car at all! :(

Bit off topic but I went to access my D2 after it'd stood a few months, the battery was flat and the key fob wouldn't open the car. I'd owned it nearly nine years and had NEVER used the key in either the door lock or boot lock. A considerable amount of WD40 and a bit of patience gained me access to charge the battery, but it's the sort of problem I didn't think of until I had it to tackle.

Lesson learned, lube your locks ;)

My boot lock was the same, which again I only discovered while I was investigating the driver's door lock issue. Couldn't even get the key in it at first, never mind turn it! It was like there was a key broken off inside; turns out it was just compacted road crud.

Lashings of lube did the trick for me too. I usually use this stuff though. Much better and longer lasting than WD40 I find.


Damn, that must've been somewhat annoying! How did you get back in (assuming you did, and the car's not still there of course!)?

Everyone probably has a favourite, this is mine: http://www.gt85.co.uk/

Never tried that one. Does that contain PTFE too? It's the PTFE that makes the big difference, leaving a long lasting coating on the parts.

Thread resurrection time!

Literally just run into this problem today as I was heading out to pick up my brother, but with a slight twist to it. The car sits out 24/7 and was last used four days ago.

The remote fob wouldn't unlock the car, nor did the key. I eventually got into the car by doing a Ctrl+Alt+Delete (disconnected the battery for a minute). Once that was done, I could then use the remote fob to open it. All good... so far.

Collected brother and once back home, dug out a spare central locking pump I bought years ago as a spare. Got that all swapped over believing that to be the problem (including the electronics box bolted to the bottom of the metal carrier) and locked the car. Waited a minute and then tried opening it again using both the remote fob and then the key, but to no avail. Ended up using the battery disconnect again. All the fuses for the central locking were fine.

Pitch black outside and a Google search later I come across this thread, and tested the unlock method with the ignition using a second key as Mark outlined. Doors unlocked fine, and I've used this procedure before during the winter time where I would start the car, turn the heat up and the front and rear demisters and then lock the car with a second key before going back inside for 10 minutes.

I've ruled the batteries in the remotes out as they will work once the car battery has been disconnected/connected and VCDS isn't recording any faults with the central locking, although I do have a leak in the boot mechanism which I noticed several months ago.

Mark - Would you still have that photo you referenced showing the connecting rod, as I'll have to investigate it?

Wow. What a blast from the past!

Funnily enough, I think I do!

I've just found a folder on my PC (dated September 2014) called 'Front Door Lock', which contained the following 2 images and PDF (attached) ...

Finally got a break in the weather to have a look at this, and from reading the PDF it looked easy. Got the door card off and had a good look around and discovered you can't get to the lock because of the door frame, so buttoned it all up again.

Had a more thorough read of the PDF and it says to remove the door subframe, and then talks about alignment afterwards. Looking at the instructions for the subframe removal, am I right in thinking that the subframe contains the window and window frame, the door stays attached to the car and that the alignment is to the window frame after refitting? Just wondering how long that would take as the instructions seem to imply it's relatively easy.

On another note and something I never noticed before as I rarely venture out after dark, but when I (can) unlock the car (after my reboot), the interior lights don't come on. However, if I then drive the car for a short drive of a couple of miles to the local shop, lock it up for a time and then unlock it, the interior lights do come on. Just wondering if one of the microswitches in the door handle is packing up and that's why I can't unlock the car with the fob (without a reboot).

Correct.

Sean I had a rear door subframe off a while back to replace the winder mechanism which had a shattered pulley, it's not that difficult.
(Bought a replacement frame from our sponsors and swapped glass, motor etc. over)
Beware losing the tricky little "thingy" on the door pull cable though! :tuttut:

Alignment on the other hand I'm not sure about, I didn't have any instructions to follow.
It seemed easy (there's only 4 bolts) but after it was all done and all the window seals looked good I noticed the bottom of the door was misaligned at the rear. :Confused:

A trick I use if I want to put the door back the way it was without realigning is to take each bolt out one at a time and put a piece of masking tape over the hole. Put the bolt back in and just nip it up again, enough to hold the frame and mark the tape but not enough to tear the tape. You can mark the tape with a sharpie if you want too. Once you have each bolt marked, also note the position of the wedge at the lower front corner (phone pic or sharpie), then you can remove all the bolts and the window frame. When you put it back in, you have marks for the various bolts :) Start with the top rear, then top front, then put the wedge in and do the two bottom ones.

Don't forget the bowden cable for the inner handle which is clipped to the back of the window frame in two places - the green clip you can see, and also a white one behind the frame.