Two problems related to brake abs warning light have been reported for the 1999 Audi A6. The most recently reported issues are listed below.
I have a 1999 Audi A6 quattro -- abs unit light flashes, diagnosed as a defective control unit. This appears to be a very common problem with Audi and vw and a serious safety issue.
The contact owns a 1999 Audi A6. The contact stated that the abs module has been replaced numerous times. The instrument panel indicates that the abs is not functioning properly. She stated that the axle on the driver side was replaced six times in three months. The dealer stated that the axle is too short. The contact stated that the parts have become very costly. The VIN, engine size, number of cylinders, and speed were unknown. The failure and current mileages were 58,000.