repeated mechanical failures of my 2022 GMC Sierra AT4, which I purchased on October 26, 2024, with approximately 37,000 miles on the odometer. The adaptive cruse control is wonderful when it works but I have found even with the sensor clean the truck will slam on brakes on its own causing me to nearly be rear ended. It happens when driving into the sun and at night. I no longer trust adaptive cruse and use manual cruse. Within just 55 days of ownership, and after driving roughly 4,700 miles, the vehicle experienced a catastrophic engine failure without warning on December 20, 2024. This failure left the truck immobilized in a highly dangerous situation—stuck in the middle of a 65-mph highway at a red light, without the ability to shift into neutral and remove the vehicle from traffic. I was forced to activate the emergency flashers and exit the vehicle, standing helplessly on the side of the road while praying that oncoming drivers would see the truck in time to avoid a potentially deadly accident. The truck was towed to the dealership the following day, December 21, 2024, where it remained for an unacceptable 110 days awaiting a replacement engine. I finally took possession of the repaired vehicle on April 10, 2025. Shockingly, only two days later—after driving just 328 miles—the vehicle suffered a second catastrophic engine failure without warning. The truck is now inoperable once again, sitting in my driveway and in need of a third engine replacement. While the odometer currently reads 42,365 miles. This ongoing situation has been not only a major inconvenience, but also a significant safety concern and financial burden. I am extremely disappointed in the reliability and performance of this vehicle. This level of failure on a vehicle that is still under powertrain warranty is simply unacceptable.