AUDI TT mk2 2.0 tfsi 2012 Remote door locking problem

[yozzer]

Problem started with battery flat caused by one of fog lights permanently on (dimly). Eventually everything stopped working. AUDI independent found that Central Convenience Unit had burnt out and replaced.
Everything now worked, but car would not lock on key fobs. It would unlock, and lock if button pressed and held to close windows, but would not lock when just pressing lock button. Batteries changed in both fobs.
Convenience Unit and keys re- programmed 3 times, but no fix.
Independent now ordering a door control module. His thinking is that it was that that caused the CCU to burn out in the first place.
He is scratching his head at the moment, and I’ve been without the car for over a month.
Any ideas would be gratefully received

[Crasher]

TT2 door lock units are notoriously unreliable, I have one in at the moment but the fact his crank thrust washer fell out allowing the crank to machine its way into the block is more of an issue, I measure 8.56mm of crank end float! Start by fitting a new door lock unit (the controller is actually the widow motor) the window drop function can be a right pain to set up accurately.

[yozzer]

Thanks for the reply Crasher. I will speak to the Independent tomorrow.

[yozzer]

Got car back today after 2 months with independent Audi garage. He can’t fix it. He has tried a door control unit but nil fix. He’s lost interest.
Both key fobs have new batteries. Neither fobs will lock the car, but one fob will unlock the car, and will close the windows if close button held.
The other fob won’t do anything.
When inside the car with doors closed, the interior door lock button will not work, but when pressing the unlock button, you hear a solenoid click.
It sounds like a coding / programming problem to me, but he says that he has done that repeatedly.
Any further advice would be really appreciated.

[Crasher]

I would start with a code read of the convenience system, can you get access to something like VCDS?

[yozzer]

Unfortunately no. If I could, I wouldn’t know how to use it.
If I took it to Audi, besides charging me eye watering hourly rates, they would probably just start replacing expensive components.
I’ve thought about using another independent.

[Crasher]

Do you have any signs of water ingress on the drivers side? Normally it is just a faulty door lock unit but sometimes the door controller fails. I have had a few Mk2 TT’s with water damaged convenience units due to the plenum chamber blocking which allows water to enter via the left hand drive heater intake blanking panel under the wiper motor. Due to the floors almost dual skin construction you don’t see evidence of it for a long time, I have driven them when you can hear the water sloshing back and forth under the seat.

[yozzer]

Thanks for that info. Interesting you should mention that, because I have had debris in the plenum in the past due to debris falling from overhanging trees. I cleared it as best I could, but must look again. I have the damaged convenience unit, and it shows burning in one corner.
I’ll look to see if there are damp carpets. Do you know where the convenience unit lives? Thanks for your help.

[Crasher]

It is up under the dash just below the blanking plate so water drops directly onto it. You will have to look under the sound insulation under the inner floor frame to see water unless it is very bad.

[yozzer]

Thanks for info. Tomorrow I’m going to remove the wipers, and then the black plastic plenum shroud and make sure the drains are not blocked. When you say LHD heater intake, do you mean blanking panel as my car is RHD? Will keep you posted.

[Crasher]

Yes, what would be the heater intake if it was LHD, under the wiper motor.

[yozzer]

To keep you updated, the car finally fixed this week! Plenum drains blocked and cleared, so water ingress causing original problem very likely.
took car to second Audi specialist who said coding was incorrect, but couldn’t fix it. Reluctantly I took car to Audi. They diagnosed that the
‘ Factory component protection ‘ was still active for the control module. They de-activated the component protection and everything now works ok. My car was u/s for 82 days. In hindsight I should have gone to AUDI in the first place . Thanks for your help.