Tl* the contact owns a 2008 cadillac dts. while driving approximately 50 mph and attempting to decelerate, the brake pedal was engaged and failed to slow the vehicle down. the contact stated that the pedal sank to to the floorboard. the vehicle independently accelerated from 50 mph to 70 mph. the vehicle was taken to the dealer for diagnostic testing. the technician stated that there was nothing wrong with the vehicle. the vehicle was not repaired. the manufacturer was not notified of the failure. the approximate failure mileage was 5,000. the vin was not available.