2020 GMC YUKON XL Engine And Engine Cooling Problems

The contact owns a 2020 GMC Yukon XL. The contact stated that while his wife was driving approximately 65 MPH, the transmission started to slip out gear and the vehicle was losing motive power. The contact's wife had not observed any warning lights. The contact’s wife drove the vehicle back to the residence and while attempting to place the vehicle in park(P), the vehicle failed to respond. The contact had the vehicle towed to an independent mechanic who diagnosed the vehicle and determined that the transmission needed to be replaced. The vehicle was repaired; however, the contact stated while driving approximately 65 MPH, the check engine warning light illuminated. The contact was able to drive the vehicle to the residence. The contact stated that while attempting to restart the vehicle, the vehicle was idling roughly with white smoke coming from the exhaust pipe. The contact drove the vehicle to a...