Driver's Door Lock

A6 All/ S6 All
#1

I’ve searched this forum and found one topic mentioning the drivers side door lock failing. My problem is a little different than their issue however.

The door does not unlock from the FOB or the Proximity Sensor. However, if I put the key in the door, it will manually unlock and I can get in no problem. So the lock itself is at least physically functional still. When I get out of the car, the FOB locks the door every time and I get the security beep.

So my issue only seems to be with remote unlocking…every other function of the door and lock still works perfectly. I’ve also scanned the car with OBDeleven and see no codes in the Central Unlocking section.

Any ideas where I should start first? Any help is greatly appreciated!

#2

I have a little bit of experience here. Does it not work for the driver’s or all keyless entry points (all 4 doors)? Typically, the system will go into a safe mode and disable if any one of those 4 connection points fails. It’s pretty easy to remove the door panels and look to see if the sensor has gone bad or if there’s just a bad connection like a pinched wire. The sensors run about $40 if I recall correctly, and as soon as the connection is restored then the keyless entry should be as well. You also should be able to pinpoint the failed connection using VAGCOM or Audi’s program from the dealer.

Hopefully this helps!

#3

None of the proximity sensors on any door will unlock the drivers door.
I will try to scan with OBDeleven again today but like I said, a few days ago when I scanned the first time, I got no codes under central locking.

#4

It is quirky little things like this that I personally find VAG-COM very useful for.

As an example: when I bought my car three and a half years ago, the telescoping steering wheel function did not work. The tilt worked but the in and out did not. A VCDS scan did not reveal any related codes. It was of no concern to me at the time.

Fast forward a couple of years and I need to remove the display screen. It is a lot easier to remove the instrument cluster panel if you can extend the steering wheel all the way out and tilt it down. It was at this time I decided to use VAG-COM to investigate the lack of the telescoping function more closely. It showed that the switch was working just fine. I then ran the adaptation and now the function is working properly.

Issues like this do not generate any codes as all of the remote mounted components are functioning fine. Sometimes the controller just needs a “slap” to relearn it how to do its job.

#5

[quote=“eng92,post:4,topic:10461”]
Ok so all you did was re-run the adaption? I’ll give that a try when I did my scan later. That would be nice if it was that easy.

#6

“Central locking” is pretty generic. Do you have a module for the driver’s side door specifically?

In VCDS, it would be module [42]

#7

My apologies as central unlocking was the wrong term. I had been looking in drivers door electronics.

I just rescanned it again and came out with this error.

http://audirevolution.net/addons/albums/images/97634010.png

Failing actuator?

#8

Can you use your scan tool to engage and release the locking mechanism?

#9

I believe it has the ability to run tests. I’ll have to check later when I have time. I’ll let y’all know once I get to it.

#10

Sorry for the late feedback. Been busy painting around the house.

I ran an output test and here is basically what happened.

The output test on OBDeleven provide either an O or I result for the locking system.

Door lock button pressed - I
Doors locked - I
Door unlock button pressed - I
Door does not unlock, however if I manually unlock the door, I still get a O response for doors unlocked in the output test.

So even with the door unlocked, the car isn’t “seeing” the door in an unlocked status.

Maybe more than just an actuator? Is it possible it might be a short somewhere in the door or something?

Thanks again for all the help y’all.
Happy 4th.

#11

The way I generally approach electrical issues is to grab a meter and a wiring diagram and start probing while using the scan tool to energize the various module outputs.

In this particular case, all you have a door module, a lock actuator and the wiring connecting the two.

I have never had a door lock actuator apart but looking at the schematic representation in the partial wiring diagram below, all I see are a DC motor and a few actuator switch contacts.

http://audirevolution.net/addons/albums/images/455975367.jpg

You can get it to lock so I suspect the motor is ok. That leaves the switches, the lock control module and the wiring in between.

If you unplug the actuator connector and use your key to lock and unlock the door, you should be able to probe the pairs of terminals described in the diagram above to see if they are opening and closing. If they are not, then you need to replace the actuator.

#12

Thanks eng92. That diagram is perfect. It will probably be a while before I can get into the door and test as time is scarce for me and she is my daily driver.

Will report back if/when I find my issue.

#13

Minor unexpected update…

The door will now no longer lock with the fob or buttons on the door either. This is making me lean more towards a failing unit as a whole, vs just a short or open circuit somewhere.

Haven’t had time to pull the door panel and do any testing yet, but that’s what I’m going to be looking at first now. 8)

#14

So my 08 S6 just started doing this very thing. Replaced key fob batteries, was working fine for a little while. Started getting colder and then the auto sense feature would intermittently not work. Then the Key fob lock and unlock buttons would intermittently work. I just went out and the physical lock just spinning with key inside not locking or unlocking intermittently. No codes, still get chirps… does anyone know what part is failing?

#15

It’s an internal lock failure. It has two electric motors, and one or both can fail. Most commonly, it starts with failing to unlock the car with a fob, but works if you unlock it with a fob and then pull the inside door handle. You can try to disassemble the lock, clean it inside and hope it fixes it. You can also replace the motors, but they don’t have any PN, as audi only sells complete lock. I’ve heard, that these motors are used in 2nd gen fiat panda, and it fits audi lock. It’s actually pretty well known issue here in europe. Most of people just replace the whole lock unit.

#16

I will just leave this here, if you are interested in a repair.

#17

Did this today, slightly different 1 motor model 4F1 837 015 F

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Cleaning the motor out, ended up removing this spring and seems to work fine. Looked like it was slightly binding the motor by being guided into the teeth by the little groove it had made.

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Reference to the orientation it goes together. You need to make sure the two plastic arms are actually clicked together. Picks and a gentle heart are your friends.

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Orientation of the way it installs inside door.

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Also broken tab on the gear module explains the key physically failing the other day.

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#18

Might be one motor on a subset of the produced cars, im guessing US sold cars, as the 2 motor lock is a safety requirement in Europe. Did you have successful results?