we have a b6 s4 at the dealership and this light was on. turned out to just be something that was not plugged back in after the headlights were buffed.

 

Im sure u have checked ur fuses. IT could be that. I think its fuse 10 that controls the auto leveling. or if u have access to a vagcom http://www.a4mods.com/index.php?page...autolevel.html

 

To get rid of that light two things need to be done, in this order:

1. Clear with a VAGcom on a leveled surface for your computer to relearn the car angle, light goes away and shouldn't come back, if it does.

2. Replace selfleveling motor (usually whole headlight assembly is cheaper about 800USD) and then use VAGcom to teach the car the angle of you new headlight/leveling motor.