Hello,
i have an Audi A6 2000, 2.8L.

if i start my vehicle, always the ABS and Brake lights are going on. can somebody help me, what i can do or what that is.

 

You're ABS unit is bad. Your brakes may be fine but you need to replace the ABS unit. They are very expensive to buy new, but I have seen rebuilt ones on e-bay for $200. Mine is on, but I live in Arizona so I dont really have to worry about rain or snow. The light is annoying though. Only way to get rid of it is to fix the unit.

 

it could be your ABS control module. it's a common problem. it's cheaper to get it repaired. try this website.
http://modulemaster.com/audiabsremoval.html