I had the same problem with my Homelink button as well. It must be the newer garage door with the rolling codes. I tried everything, went to the website. Finally I had enough and went and bought a new garage door clicker (I had lost the 2nd one).

2004 Audi A6 S-Line 2.7T

 

I followed majadams5 and it worked. I feel like a genius now.

 

I was also having tough time with my 2003 Audi A4 station wagon. In my experience, key 1 worked key 3 did not. So, moral of story is that not all keys are alike. As long as some key is working, its good.

Instructions by mustang196718 and mjadams5 are same. I tried mjadams5 instructions. It worked for key 1 but it did not work for key 3. Dont know why but Im happy.

Audi is new for me. I learned today that I cant buy any wiper of size 22 from any shop even. I've owned cars for looooong time but I never had this wiper issue ever. No other comments other than, its audi.

Abbas