The contact owns a 2019 GMC Terrain. The contact stated that occasionally while driving at various speeds, the vehicle independently shifted into neutral(N) and the vehicle lost motive power while the accelerator pedal was depressed. In addition, the vehicle had shifted from park(P) to drive(D) and into neutral(N). There was no warning light illuminated. The vehicle was taken to a local dealer, where it was diagnosed; however, the cause of the failure was not identified. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 45,000.