Brake Electric Antilock problems of the 2003 GMC Savana

The contact owns a 2003 GMC Savana. The contact stated that when applying the brakes at speeds of at least 50 mph, the anti-lock brake would engage, forcing the petal back into the idle position and causing reduced braking response. The contact confirmed that the anti-lock braking light would illuminate on the instrument panel moments before the failure would occur. The failure mileage was 37,000 and the current mileage was 50,000. The VIN was not available. Updated 05/19/10.