Hi there everyone, I am seeking a little advice here please, I have just bought a 2005 A4 estate and the central locking doesn't work. I have two keys, both emitting a signal and a good auto electricial has tried all ways to code them to the comfort unit but without success. I have changed the comfort unit for another second hand one with matching numbers and this won't code to the keys either. Both comfort modules do everything else the should such as Windows, climate etc. Any ideas anyone. Is this a common fault? is the second module also likely to be faulty on the c/locking bit too?