I've seen a few things on here about this but they're pretty old so wanted to re-post. i've got a 2008 A4 tdi and the remote central locking has suddenly stopped working. i thought it was the fob, but i tried the spare and that doesn't work either. also the red light does flash on the fob when pressed. i have to manually open the drivers door with the key, then push in the ignition to unlock the other doors from the inside. any ideas?