Audi A4 - Door lock and alarm problems

hI I have rear door locking problems all else is work exsept the alarm I take it as the rear doors are not locking the alarm will not set.
It all started sometime a go took it to audi they advised for £50 that I have water in the N/S foot well big bill. So I removed the front seat pulled
all trims off lifted the carpet and loads of water AND the designer has fitted the control unit there clever.
I found the the plastic cover on the pollen filter unit had a split along the back flange this is were the water has been getting in I think mainly
because I park on a slope. Repalcement was about £3 done all dry,
I have now managed to get a spare convenience unit and need to fit it soon. Any leads I understand that the keys need codeing hope to do this
with Vag com software then do I need to run vag com to sort out the locking problem. I also understand that the keys will need codeing to the emobilizer or can this be done with vag com I don`t have the SKC code.

i think your supposed to get the coding for the old control unit via vagcom so you can code replacement unit (depending how much damage - not always possible). Not sure if you will have to touch the keys. I'll try & get more info.

I think my last post correct but keep ignition off untill replacement connected & coded & shouldn't need to touch keys.
John

Vag-com can not see the old unit I have fitted another unit all seems ok but the keys only work in the drivers door no remote.
I have tried key coding can not sort it out. The rear doors are still not locking Vag com shows the rear doors are in safe mode any ideas this may
be the problem.

Did you ever get the problem sorted?

I have a similar problem on my S3, and looks like I need a new convenience unit... Is it a straight forward swap out or is there a need to visit the ******* for it all to be recoding?

Thanks for you help in advance...

Hi

On the A4 biggest job is lifting the carpet and socking up the water took me
around a week with towels and paper the carpet is foam backed which is were all the water collects.
If on the a3 the unit is under the carpet once you lift it the unit should be
in a box open unplug fit the replacment.... New or from a breakers.
Online breaker sites just fill in the details of what you want someone will contact you.
Pull up the carpet get the part number from your unit ******* dealers if there like my local will not give out part numbers.
If you have Vag com this will give you the unit Number.
I got mine from Ebay.

Once the unit is in place you will only have to get your Keys coded again
I done mine with Vag com handy tool to save money on fault codes most
garages change £40 to read fault codes may have to pay a bit more to get the
keys done.
Can be done your self just need to get software and details on how.