Door Lock Problem
 

I have a 2008 A6 S-Line. About a week ago the door lock started acting strange whether I locked the doors with the button under the door handle or locked the doors with the key fob. It does not beep like it is supposed to and like it has for 10 years. When I hit the door lock the alarm light blinks very fast for 6 or 7 times then glows a steady red. After about 20 seconds it starts blinking normally to show the alarm is set. Any ideas on why this started occurring? Is it something to worry about (if I wasn't already worried I wouldn't be posting this!)? Could it indicate my battery is getting weak? It's been about 4 years since I put a new battery in the car. Thanks to everyone who can help!! Jon

I'm having the exact same issue with a Q7

Door lock
 

I had the same issue, replace the passenger door lock and all good now. That door lock wasnt working at all. The central locking wont beep if is any door open, i will once is closed.