The contact owned a 2012 Kia Optima. The contact stated while driving 65 MPH, the vehicle lost motive power and was driving slowly. There was no warning light illuminated. The vehicle was taken to the dealer; however, no cause for the failure was found. The vehicle was not repaired. The contact stated that the failure persisted. The contact stated that recently, while driving 65 MPH, the vehicle lost motive power and stalled with an unknown message displayed. The contact was helped over to the side of the road. The vehicle was restarted. The manufacturer was made aware of the failure. The failure mileage was approximately 20,000.