Open door warning does not show for driver's side doors, no dome light w/ doors open.

[apontnack7]

Hi folks! Just wanted to preface with saying that I'm very excited to be a part of this community. I have grown to love my Audi over the last couple of years and I greatly appreciate the effort put forth to sustain a community like this which offers help for other (sometimes slightly less car-savvy) individuals, as well as a place for enthusiasts to meet and share ideas. Hats off to you guys!

On to the issue. I'll try not to make this explanation too long, however, I do think it's best to start from the beginning and be thorough so that users can have that information available when they help out instead of having to ask more questions about the problem. To preface, the vehicle is a 2001 Audi A6 4.2 (c5).

Several months ago I noticed that there were water spots in the headliner on the C pillar, passenger side. With some research (on audizine!) I was able to diagnose the problem. I decided that the most likely culprit was the sunroof drains being clogged or otherwise not functioning properly. I knew that I needed to pull back the headliner and check, but I was unsure how to tackle the issue. I decided to take it in to a local car interiors shop here in Chicago, and they were very knowledgable about headliners, sunroof drains, the whole shebang. They pulled down the headliner for me, found the issue (the hose was disconnected near the C pillar, passenger side!), fixed the issue, and replaced the entire headliner. I thought all was well until they started telling me about the extent of the water leakage. They said that they found the footwells to be damp, especially the front driver's footwell and attributed this to the leakage of the sunroof drains. I do believe this is possible, however I have read information (here on audizine!) about faulty battery tray (?) drainage causing wetness in the driver's footwell. So this brings me to my first question, what likely caused the leakage? Have I likely fixed the problem, or is the water drainage from the battery more likely the culprit? I figure either way, I should check to make sure. However, I figured this would be a good place to ask for comments/suggestions about that situation.

The reason why I explained the above issue first is because I believe it to be directly related to the larger issue at hand. I believe these to be related to the dampness of the footwells only because I did not notice this issue before this happened. The issue I am having is related to the doors, interior lights, and the "open door warning" indicator on the cluster's display. I will break down what is happening in bullet points because I feel it's easier to understand the separate issues and how they are related.

-- The driver side FRONT door -- does not trigger the dome light, does not trigger footwell light, and there is no "open door warning" on the cluster's display.
-- The driver side REAR door -- DOES trigger the dome light, does not trigger footwell light, does not trigger the "open door warning" on the cluster's display.
-- The passenger side FRONT door -- DOES trigger the dome light, does not trigger footwell light, DOES trigger the "open door warning" on the cluster's display.
-- The passenger side REAR door -- DOES trigger the dome light, DOES trigger footwell light, and DOES trigger the "open door warning" on the cluster's display. (only one working completely )
-- The TRUNK -- DOES trigger the "open door warning" on the cluster's display.

The research I have done here on audizine has led me to three possible problems (probably a combination of the three, actually): either the CCM is malfunctioning from the dampness in the driver footwell (no sign of damage to the CCM, though it was damp), OR the door latches are malfunctioning (I've read about door pin switches, microswitches, and sensors within these latches that can malfunction), OR the wiring/lighting units themselves are damaged (or bulbs need to be replaced!).

I could go ahead and replace 3/4 door latches and the CCM, and I feel this would most likely fix the problem. However, I'd first like to check to see if anyone else has had this problem and/or knows exactly what I'm talking about and knows the culprit from the breakdown I just gave. So, I come to you great members of audizine for assistance with this matter. Any direction/comments/suggestions that any members can give me about this issue would be greatly appreciated! I will be following this thread closely as I settle into my nice little audizine nest :)

Thanks so much for reading my wall of text and for any help in advance, it is much appreciated!

[apontnack7]

I guess this is a crucial piece I should have added in the original post: The only thing that I am POSITIVE started happening since I noticed the damp drivers footwell is the front footwell lamps being out (when opening either front door) and the driver's door not triggering the dome light. Also something the add, the small red lights on the door cards on both driver side doors do not work , while both work on the passenger side doors. AHHHHH!

[Vinnie981]

sound like your comfort control module got wet or your door contact switches are wacky

[apontnack7]

sound like your comfort control module got wet or your door contact switches are wacky

Yes, or both! It seems like I might switch out all the latch actuators and the ccm. Anybody have a model number on the 2001 c5's CCM?

[rogersb6]

First fix your leak.

Then, if the problem hasn't gone away, replace your CCM.

The latch actuators are least likely to be faulty if 3/4 are not working properly. More likely that the one thing controlling them is at fault rather than 3/4 mechanisms failing at the same time.

[Audiudo]

My guess is the microswitch. If the CCM was going bad I would assume more controls would not work. e.g. sunroof, windows etc.

[mike2112]

def microswitch

[apontnack7]

Is the microswitch part of the latch actuator unit?

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[rollerton]

Is the microswitch part of the latch actuator unit?

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Yes. It's on the door latch, and the micro-switch very likely still functions perfectly. Replacing the latch is the easiest way..but I replied to your other thread too...

[Hendrix_128]

I had a similar problem but mine was a short in some wiring in the driver's seat. had to strip it down to the frame to find it and it kept blowing fuses. I'd suggest what they said, but if none of that works, start looking for shorts.

[Camelian]

The micro switch has been a problem on SEVERAL....take that back....EVERY A6 I've owned. I've taken the latch out, removed the micro switch and repaired them on all of mine. The switch gets worn out and does not trigger. I take a soldering iron and melt some plastic from a wire tie and plastic weld it to the plastic of the switch. Has worked every time. It's a small part but not very hard to do. You can test the wire first with a probe. Just take your door panel off and you will see the two wires coming from the bottom of the latch assembly (once you take the plastic shield off. Then manually close the latch on the door with a screwdriver or something. Hope this helps. If it ends up being the CCM I have a spare that I could sell you cheap just pm me. Good luck!

[arjun90]

Time to resurrect this thread.

I have the same problem, but this only pertains to the driver side Front Door, also the Sun-Visor Mirror Light does not turn on either.

How does the microswitch look? Does any have a picture? Can the microswitch be swapped or would I need to replace the latch as a whole?

The micro switch has been a problem on SEVERAL....take that back....EVERY A6 I've owned. I've taken the latch out, removed the micro switch and repaired them on all of mine. The switch gets worn out and does not trigger. I take a soldering iron and melt some plastic from a wire tie and plastic weld it to the plastic of the switch. Has worked every time. It's a small part but not very hard to do. You can test the wire first with a probe. Just take your door panel off and you will see the two wires coming from the bottom of the latch assembly (once you take the plastic shield off. Then manually close the latch on the door with a screwdriver or something. Hope this helps. If it ends up being the CCM I have a spare that I could sell you cheap just pm me. Good luck!

[Racin2redline]

I just changed 2 microswitches yesterday. Drivers and rear passengers. They are pretty easy to change. You just need to remove the door frame. It's like 4 torx t40. I just replaced the whole latch mechanism because I have so many spare ones.



BUT, if your vanity mirror is not working. I would pull it out and check the wires. They have been known to sever themselves over time and cause some electrical shorts.


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[arjun90]

Are the microswitches part of the latch, or can they be sourced and swapped separately?

I just changed 2 microswitches yesterday. Drivers and rear passengers. They are pretty easy to change. You just need to remove the door frame. It's like 4 torx t40. I just replaced the whole latch mechanism because I have so many spare ones.



BUT, if your vanity mirror is not working. I would pull it out and check the wires. They have been known to sever themselves over time and cause some electrical shorts.


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[Racin2redline]

Believe they are part of the latch, where the red and blue wires run to. Some people take them off and clean the switch, not really sure I've never pulled it apart


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[Avantugofast]

But what if NONE of your open doors trigger the LCD open door display or the open door tones. lights. Is this the CCM? Windows all work fine.

[vlangs]

I hate thinking about this because my driver door has had the same problem since a particularly icy winter jammed the door lock one day

I have those audi projector lights in doors and the one door i use the most doesn't trigger!

but swapping the switch is just not something i'm willing to do at such considerable cost

[rollerton]

I've learned that there are two things that can cause the doors not registering open/ closed. 1. It's the microswitch on the latch. 2. It's the wiring in the door jamb.
I have never had a Central Locks / or other module fail and cause this problem alone. If you have evidence of water intrusion then by all means, investigate. But about 90% of the time it's the latch, 9% it's the wiring and 1% is other causes.
There's just simply no way around it. If you're hardcore you CAN simply delete the door latch microswitch and run one of the wires to a regular old-timey door pin switch that grounds when the door opens. Problem solved literally forever. I've done that for people on a budget, and can verify it works. You just have to do some careful checking where you install the spring loaded door-pin thing.
Otherwise, I have bought the Chinese made cheap door latches off Ebay, and ...well....they work. No problem. And the shipping these days is super quick; I don;t think it EVER take two weeks to get stuff these days. Many times less than a week.

[vlangs]

mine is the microswitch on the latch

i can manually switch it on and everything else will register just fine

i guess it doesn't bother me quite that much tbh, otherwise i'd have switched it a long time ago

[arjun90]

Are the micro switches the same part number for all four doors?

[Hfpedersen]

Sorry to resurrect this but I now have the same issue. Dome light stays on, auto lock will not work and interior lock button will not work on either door.

My question is if there is a way to narrow down which door latch I should replace? Dash does not indicate any doors open when having these issues. Instinct says its the drivers door as it sees the most use but I don't like buying parts on instinct!

[C5S6]

Sounds more like a wiring problem to me...You might peel back the rubber boots in the door jambs to see if the wiring appears to be the issue.

Symptoms of the drivers door latch microswitch failing are easy to diagnose. If working correctly, and you open the drivers door, the mileage, clock etc. will illuminate in the instrument cluster.
This should be a valid test even if it is another door switch. When all is operating normally, after a few minutes with any door(s) open the dome light will turn off on its own so try the drivers door after no activity with the car for 5 min or so (key out also).

I don't know for sure that the auto lock is a good indicator of anything. Our '03 A6 auto lock has worked intermittently since we bought it 8 years ago.

[Hfpedersen]

Thanks for the reply. Turned out it was a disconnected harness behind the RF door card. I believe it was the harness for the two lights under the door. All locks and dome lights work now.
LR door still does not appear as “open” on the dash lcd but it activates all the lights when open. I can live with that though.