One problem related to automatic transmission control module has been reported for the 2000 Audi Quattro. The most recently reported issues are listed below.
Wheels loses traction on slick road conditions causing driver to lose steering control capabilities. Dealer has been contacted. Consumer states that when vehicle is on ice or packed snow and the tires are at their limit of adhesion, the center differential senses slip in the front or rear wheels and transfers power to the other end of the vehicle, this causes vehicle to break traction at that axle and the differential switches power to the other end, breaking it loose once again.