Why won't my front passenger door lock?
 

I can't get the front passenger door to lock. It does not lock via the key fob, the key itself, or any of the buttons under the door handle. When I lock the car there is no "beep." The alarm light blinks rapidly 6-8 times, the light then stays red for 5 or more seconds then it blinks normally like the alarm is set. But the front passenger door is not locked. Anyone can walk up to it and open that door, but none of the others. A few months ago I noticed when the auto locks came into play at about 15mph there was a hum from the front passenger door while all the others gave off an audible "click." I hate not being able to lock my car. Is this an easy fix? Something I can tackle? THANKS!

What model is it? I have an A6 C5 that had something similar and it was the door lock micro switch... not a too difficult job - depending how good you are with the tools :) Search my posts as I think I did a write up.

door latch micro switch repair:

https://www.audiforums.com/forum/aud...cement-191539/