The contact owns a 2016 Ram 1500. The contact stated that while driving on the highway at 45 MPH, the tailgate unexpectedly opened. No warning lights were illuminated. The contact pulled over onto the side of the highway and closed the tailgate. The contact drove the vehicle to a local dealer where the vehicle was diagnosed, and the contact was informed that the lock actuator was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 118,000.