While traveling on the interstate the vehicle lost all propulsion and started to rapidly decelerate. Shortly after propulsion was lost the engine turned off completely affecting the steering and braking of the vehicle. The vehicle was towed to the GMC dealership that we purchased it from. repairs have not begun so I assume it would be available for inspection. We were traveling on a three lane interstate up a grade at 80 MPH. Had I not been able to safely get the vehicle stopped and out of traffic or had we lost control going down a grade we would not have been able to stop the vehicle and there would’ve potentially been a catastrophic accident most likely resulting in injury or death. No the dealership has not diagnosed the failure physically. The service writer did suggest that it sounds like the failure reported from the recall not being addressed. I did contact the dealer about the recall on Saturday May6th. At which time I was informed there was not a solution for the vehicle for my vehicle at that time. There were no warning prior to the incident. After the engine stopped operating there was a warning produced on the instrument panel that read ‘Engine Oil Hot’ and the instrument panel no longer registered any oil pressure.