A6 1995 interior light fault

[brighton123]

Evening all, My interior light does not go on when you unlock and open the door but comes on with the switch, Possibly related, I changed the dash bulbs behind the instrument cluster that light the odometer and the trip computer. When I switch on the headlights these go out instead of dimming. any ideas? I have another A6 same model same year which I am using as a donor car so can swap out any bits for testing, The donor cars dash lights dim and the inerior light comes on when you unlock the door, any thoughts gratefully recieved.

[brighton123]

Done what I should have done in the first place and had a look through the old posts. I suspect the comfort control module is at fault as I had a huge puddle in the passenger footwell, although none in the plenum chamber strangely. Is it possible to swap the CCM from the donor car. the donor does not have remote central locking and the car in question does. Also does the CCM also control the air flow round the car, just wondering as the screen does not clear ie no air comes up through the vent under the screen. will I disable the cars If I swap the CCMs over that is my biggest worry, many thanks

[Peter D]

There are two sources of this water leak. One is a block plenum chamber which you should check by hosing down the windscreed then opening the bonnet and looking down the dise of the battery for retainsed water. The other is a failed seal where the pollen filter seal to the metal work and leaves blocking the back corener of the unit. First thinf to do is remove the kick panel and the sill trim and lift eh carpet. I have resued many of there by rmeovine it form the the case in which it sits and drying the CCM out ans all the cable harnesses and carpets, two days with a fan heater carefully aimed under proped up carpets can do the trick. However be aware that water will have run backwards and the rear undercarpet will be wet as well. Regards Peter

[paul b]

Done what I should have done in the first place and had a look through the old posts. I suspect the comfort control module is at fault as I had a huge puddle in the passenger footwell, although none in the plenum chamber strangely. Is it possible to swap the CCM from the donor car. the donor does not have remote central locking and the car in question does. Also does the CCM also control the air flow round the car, just wondering as the screen does not clear ie no air comes up through the vent under the screen. will I disable the cars If I swap the CCMs over that is my biggest worry, many thanks

As Peter says you're best drying the CCU/CCM out trying to save it.

I would not use a second hand CCU. I would imagine you need another CCU from a car that had central locking, as I don't think all the correct pins would be there. They are not necessarily plug and play either, a used one will need coding to your vehicle with VAG-COM/VCDS or something of the like. If you have VAG-COM try communicating with the old CCU and pull the softcode from it, write it down and use that code to re-code the new CCU. Audi will do the job but will charge a little extra for coding.

The car will not be disabled if you remove the CCU.

[brighton123]

Thanks for the responses, I actually removed the entire interior from the car including the carpet, which was a bit of a mission as you might imagine! I hung the carpet up for a week to dry it out when we had some sun and put it back once the foam was dry, when I did this there was 3 litres of water in the footwell ! I drilled a small hole under the CCM to drain this as I could not see any other way! I did not actually remove the CCM as I took it to be the main ECU and thought I might disable the car It was drying out though for a week though albeit still plugged in, The battery in this 95 A6 is not under the bonnet it is under the back seat, where you would expect the battery to be there is the fan workings. I guess I should unplug and remove the cover from the CCM then ? and dry it out, also I guess I should further investigate the plenum chamber for pollen filter leak or else I will get the same prob again in a few months?