The contact owns a 2016 Ford F-150. The contact stated that while exiting the driveway driving approximately 20 MPH, the vehicle unexpectedly downshifted. The vehicle failed to accelerate or move forward. There were no warning lights illuminated. The vehicle was towed to a transmission specialist who determined that a transmission replacement was needed. The vehicle was repaired, but the failure recurred. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted and confirmed that there was no recall coverage on the VIN. The failure mileage was unknown.