THE PROBLEM STARTED ABOUT A MONTH BEFORE THE INCIDENT. THE ABS LIGHT WOULD COME ON INTERMITTENT. AFTER A WEEK IT STAYED ON. WHEN THE LIGHT WAS ON THE BRAKES ACTED NORMAL EXCEPT NO ABS FUNCTION. I WAS DRIVING TO WORK (ABOUT 30 MPH) AND STEPPED ON THE BRAKE TO SLOW FOR A CURVE. WHEN I STEPPED ON THE BRAKE THIS TIME, I NOTICED THE ABS LIGHT WENT OUT AND THE VAN JERKED VIOLENTLY TO THE RIGHT. ON TO THE MUDDY SHOULDER AND INTO THE GUARD RAIL. *TR