The contact owns a 2021 GMC Yukon XL. The contact stated that while driving 65 MPH, the vehicle shut off with the message to restart the vehicle displayed. The contact was able to pull over and restart the vehicle after several attempts; however, the failure reoccurred soon after the vehicle was restarted. Due to the failure, the vehicle was initially towed to a dealer but was later towed to an independent mechanic. The mechanic performed a diagnostic test and diagnosed the vehicle with engine failure. The vehicle remained in the possession of the independent mechanic. The manufacturer was not notified of the failure. The failure mileage was approximately 60,000.