AT HIGHWAY CRUISING SPEED, WITH THE CRUISE CONTROL ON, THE TRUCK SPONTANEOUSLY LOCKED UP THE WHEELS AND WENT INTO AN UNCONTROLLABLE SKID OFF THE INTERSTATE HIGHWAY INTO THE DITCH AND UP THE EMBANKMENT. THE FORD DEALERSHIP WHICH FIXED IT FOUND A COMPUTER ERROR CODE P0975, AND THEREFORE REPLACED FORD PART NUMBER 9L3Z7A100C:CONTROL ASSEMBLY-TRANSMISSION. NO BRAKING SYSTEM PROBLEMS, AND NO REAR END DIFFERENTIAL PROBLEMS WERE FOUND. THE TRUCK WAS DRIVABLE AFTER THE ACCIDENT. IF THE TRUCK HAD ROLLED OR STRUCK AN OBSTACLE, FATALITIES COULD HAVE RESULTED.