So I recently lost the key to my 04 A4 and had the dealership tell me that in the process of it being towed the Comfort Control Module went out and that it would cost $900 to fix. I decided to buy the part myself for $150 and install it myself. Prior to installing the new one the alarm would go off at any opening of doors or the car starting and only 3 doors would lock. Eventually the car would not start with the newly programmed key. I installed the new CCM and the car fired right up and the alarm doesn't go off, but now I can't lock the car (particularly driver's side front door won't lock from inside or out) and other small issues including the dome light staying on while driving occasionally and the seat belt alarm not going off despite the only person in the car being belted. Any advice?

 

faulty module would be my first guess..

 

I had my comfort control module go out on me aswell and the same things you described is what happened to me. I had the dealership fix mine it was nearly $1100 . How hard was it to do this yourself?