My ABS and brake light have been coming on in the past couple of days. They both will come on momentarily along w/ a couple of beeps and then disappear. I did a search and I guess the ABS module is the usual cause. I'm new to Audi and have had my B5 for maybe 4 months now. I don't have a VAG but I will get scanned as soon as I get a chance.
I had the same problem, the Module can only come from dealer shipped and installed for 650$ OR!!!! You can go to the website below and have yours rebuilt for $175+ shipping. I had mine repaired by them and it works perfectly now. I realized with out my ABS sensor I went through pads and rotors in twice the time.
I didnt remove my module I had a shop do it since they were already replacing my clutch, they gave it to me, I shipped it to Utah, they repaired it in 2 days shipped it back and I had my shop reinstall.