One problem related to air brake abs warning light has been reported for the 2003 Mercedes Benz 320. The most recently reported issues are listed below.
When the car was two months old, 1500 miles, a warning light came on telling me that my brakes may not be working and that I should stop driving immediately. In fact the brakes were not working and I had a hard time stopping on the side of the highway. The car was towed to knauz mercedes in lake bluff. They still have not told me what went wrong but say that they have gotten new parts and the brakes should be fine.