Convenience module location?

[Adrian E]

This is on the A6 mate

On that there's 2 bungs in the plenum area which I cleared at Xmas when they blocked up and drained into the cabin - its still bone dry in there as first place I looked

I had the air-con regassed the day before we went on hols and suspect now its working at full capacity the drain isn't coping with the condensate. No puddles under the car when its parked

[notorious]

Oh A6... Apologies...

[Titan]

Might be too late if you've had it sorted but the module is under the front passenger carpet. If you take off the cill cover and front passenger doorbell plastic trim, you'll be able to prise up the carpet and pull out a black plastic box the size of a video cassette case. The module is in there. You can just about drive with the box above the carpet until the leak is sorted.
I've had lots of experience fixing this on a few C5 models so feel free to pm me and I could pass any info over the phone.
Grant

[Adrian E]

Cheers Grant

We've been home from holidays nearly a week and I managed to strip the carpet back following this guide:

http://forums.audiworld.com/showthread.php?t=1675861

This is pretty much what I found:








The box containing the module had enough water swimming around under it to be causing problems - certainly poured a fair bit out!

I could only get 2 out of 3 bolts out for the evaporator funnel - don't know if the 3rd is even less accessible on a RHD car than LHD but even with a 1/4" drive socket set with uj or flexi coupling I couldn't move it more than a tiny bit. With 2 out I managed to get it out of the hole to blast both ways with compressed air (not a proper go 'upstream'). I also rodded the upstream end with a brush I've got for cleaning out my mountain biking water bottle pack! The valve end didn't seem to be blocked anyway.

I now have condensate dripping out of the car by the lifting point near the subframe - I'm not convinced it was coming out of there before I did it. What I can't see is where the water was getting into the footwell as there's no evidence of it tracking down from the funnel/valve area? I'm wondering if it's double skinned by the valve and was tracking back or if it backs up high enough to end up coming out of the rear passenger floor vents?

At the moment the front seat is still in the car but the carpet's been propped on the seat all week and lifted up as much as I could achieve. I've been leaving the car parked with windows open during the day to try and bake the water out, which seems to be working.

I've had no repeat of the indicator lights shorting out. The remote central locking was doing odd things - it would lock the car and if you unlocked it immediately it would work. Leave it half an hour and it would've 'forgotten' the remote until you switched the ignition on again. Last couple of days that odd behaviour has also stopped.

I've bought some WD40 contact cleaner which is also supposed to clear water residue and my plan over the weekend is to fully remove the module from the car to do that, plus clean up all the sockets as I can see some signs of water entry around the multiplug terminals.

I bought some silicone grease but I don't think that's the same as contact grease so probably not advisable to use on the individual pins?

Any other advise on things I should check or do before starting to put it back together? Once I've got it sorted I'll need to find someone to clear the airbag fault codes. I thought by turning the passenger bag off in the glovebox and running it like that it wouldn't throw a fault with the glovebox removed? It has anyway.....

Cheers

Adrian

[Titan]

I think you are almost there. Using a contact spray on the circuit board of the module and cleaning up the connector pins sounds spot on.
The fact that the central locking etc is back to normal and the indicators have stopped flashing leads me to think you've managed to get away with it after the module has dried out (fingers crossed)
I'll jot down some ramblings below and hopefully you can take something from them!

The first time this happened to me was on a 1998 car with the same symptoms as yourself with the indicators flashing, central locking going funny etc. I bought a diagnostics lead and downloaded Vag-com which stated the crash sensor had an error. The Audi parts diagram told me this was under the passanger seat and I ultimately found the area swimming. The crash sensor must have been short circuiting and thinking there had been an accident, unlocking the doors and getting in a right fankle. The source of the leak was the plenum chamber drain holes being blocked, so I unblocked them, dried out the module but still had no central locking or indicators.
I got a replacement convenience module from ebay for £40, stuck it on and as soon as I copied the code from the old one using vag-com everything worked.
I think the crash sensor had caused the airbag light to come on but I'm sure I was able to reset that with vag-com. It was so long ago I did this one I may be making this bit up.

The second car was slightly different. Same source of leak and symptoms but this time I dried out the unit, fixed the leak and it was all perfect. No re-coding etc required. Lucky.

The third car (you'd think I'd have learned by now......but it belonged to a friend!)
The condensate outlet from the evaporator was blocked and the module was flooded. The central locking had never worked and the indicators had been flashing when the module was wet.
This is the interesting (honest) part.
We took out the 4 or 5 plugs from the module and then opened up the plastic case to reveal a circuit board which looked a bit corroded.
With nothing to lose, it was cleaned with a toothbrush using bicarbonate of soda mixed with hot water. Once it had dried, I used a contact spray on it like you mentioned above to dry it out properly and disperse any traces of water. I cleaned up a few of the individual wires going into the connectors that had a bit of surface rust, plugged them in and everything worked again.
I can't believe the circuit board stood up to being under water for so long followed by the bicarbonate and tooth brush treatment but it did.
I'm still getting the odd bit of solder in my mouth when I brush my teeth though.....

Finally, not sure if you have checked this but I also had to reseal the pollen filter housing under the bulkhead cover on one of the cars but can't remember which one. This is normally worse if the bung holes are blocked at the bulkhead (which yours are not) but it is possible for some water to run down the windscreen and in, if the plastic bulkhead cover or the other thinner one the wiper arms go through are cracked.
If you take the pollen filter out there are a couple of bolts holding the housing in place. Remove these and check the underside of the housing. There is a rubber seal all the way round which perishes. I cleaned it up, put silicone all round and re-seated it. I'm sure Audi will do a replacement seal as well which is not as messy a job

Good luck.