Hey i have some unique electrical problems that im hopin someone can help me out with... i recently has some water spill in the back seat(passenger side) of my 2001 A6 2.8 Quattro. The next day my dash computer said that 3 doors were open when all were closed (pass., both rear); also my windows do not work, the sunroof dont open, and my remote works to lock/unlock but the alarm does not set as the car thinks doors are open.

I have searched the forums extensively and have tried unhooking the rear footwell lights on both driver and pass side as suggested, replaced the fuse and it lasted about 3 hours and then blew again. I dont seem to be doing anything different or out of the ordinary when it blows and cant really connect it to anything.

Also i have seen in the forums that sometimes the comfort control module can be the culprit..... could it be something else related to the back seat????? that is where the water spilled, not the front. i would like to rip up as little things as possible.... also, what tools can i use to test that stuff?

 

My bet is on your comfort control unit. Foot well lights are not related to your symptoms. Pull out your seat, lift up the carpet and dry the thing out.

But get more advice first before ripping the seats out.

 

You should lift the back seat to see if you still have water. You you have to do is just pull it up. FYI, plastic clips holding the seat tend to break easy, but you can get a replacement from the stealers for pretty cheap. Anyways, soak up all the water and dry the seat out for awhile. If you have heated seats on the back, you have 4 total electrical connector attached to the back seat, 2 each per side. Dry those out and see what happpens.

Also there are a couple of wiring loom on the passenger side going to the rear. Make sure those are dry as well.

 

Do you know if any water got to the front driver floorboard? I recently bought an 02 A6 2.7t that was flooded and had very much the same symptoms as you are experiencing. I would guess that water has gotten into the interior control module located under the carpet just in front of the drivers seat. Once water gets into the box it needs to be removed and drained. Also I would check the trans control unit located in about the same position just in front of the front passenger seat.

The interior control module is more than likely what is causing your side window problems but not the sunroof. The sunroof issue is probably a bad connector in the wiring harness. If you pull up the carpeting in the drivers floor area you will see that the main harness runs along the drivers door sill. You need to pull that harness apart and in several places along the sill and also in the area where the harness runs under the front seat and goes back in under the center console you will find butt splices inside the harness. These splices do not like the water as the splice itself is aluminum and it is covered with a rubber boot when water gets into the boot its trapped and the splice corrodes until the wires just start falling out of it. Just look carefully at these splices and tug gently on the wires going into them and you will find the bad ones in short order. I would recomend cutting them all apart and soldering and heatshrinking them to avoid problems in the future.

The interior control module is also what causing your issues with the dooors showing open as I said your problems are exactly the same as what I had with my daughters car. feel free to pm me if you have any questions. Somewhere I took some photos of the locations and repairs of the harness I will find them and post them up.

 

ok i checked the rear seat wiring and they seem dry. it wasnt a whole lot of water that spilled and it was actually like a week ago, this is the first chance i've gotten to diagnose it. so looks like im gonna have to remove the drivers seat.... any advice for lookin at the comfort control box? what i should be lookin for besides water, and if there is corrosion what should i clean it with? hopefully i can just clean it and it doesnt have to be replaced. any help is appreciated.

 

yea thanks for the advice padog. i dont have a soldering gun but i do have some in line squeeze connectors.. i dont know what their called but the kind that you use for hookin up aftermarket car audio decks. will that work, i can get some heatshrink.
also i was noticing in other posts that sometimes this water can come from the drains clogging and overflowing onto the floorboard. where are the drains? i definately want to clean them out so this doesnt happen again....

 

The drain should be behind the firewall, somewhere under the cowl in between the battery and the HVAC.
( I would assume your quattro has the battery behind the firewall)

 

The drain should be underneath the battery you will need to remove the battery and the battery box to be able to get down in there and clean it out.

you dont have to remove the seat to check the interior control module. If you remove the sill trim and the trim in front of it in the footwell and move the seat all the way back you can pull the carpet back enough to see the black plastic box that contains the module it is actually located in front of the seat. everything around it may appear dry so be sure to open the box to look for water. unfortunetly if it got much water in it it is probably already ruined but maybe you will be lucky and drying it out will work. You will need to remove the seat if you find you have corrosion problems because a couple of the splices that go bad are in the harness that runs under the carpet under the seat.

Also like I said be sure to check the trans controller in the same spot on the passenger floor as the water usually leaks in on that side and also gets into that one as well. the faster you get them dried the better off you are. I would also recomend putting dielectric grease into the connecters before reassembling to stop further corrosion.

 

aite thanks a lot guys.. im headed to the auto store now for some supplies and ill keep ya posted on the outcome.

 

ok pulled the drivers side carpet up and checked that out.... no water or noticable damage of any sort. i did notice that my remote wire to my amp had a good 2 in. section of surround missing and it was grounding out on the body. Put electrical tape around it and put back together thinking that had to be the problem.
replaced fuse and drove fine all evening.... then i went to turn on my front dome lights, the red flashed for a second and then out. now all the original issues are back, windows dont work, three doors open, no alarm or sunroof.
tomorrow i will check the passanger side just to be safe but i doubt i will find anything bad.... then maybe check the wiring for the dome light since thats what made it short out???? i want to get this fixed, its getting quite annoying....