SEVERE BRAKE LINE CORROSION AND CORROSION AT WHEEL SPEED SENSORS CAUSES ABS TO ACTIVATE AT LOW SPEEDS. I HAD 2 NEAR MISS CRASHES AND THEN CAR WOULD NOT STOP AND I HIT A FENCE IN MY YARD YESTERDAY. I HAVE 4 OTHER VEHICLES , A DODGE, BMW, AND 2 HONDA, ALL OLDER THAN THIS ONE, AND DO NOT HAVE THE. CORROSION ON THE BRAKE LINES. THERE IS AN ISSUE WITH THE MATERIAL USED IN THE GMC BRAKE LINES THAT CAUSES IT TO SEVERELY CORRODE. MALFUNCTION OCCURS INTERMITTENTLY.