While driving on the freeway, my truck suddenly experienced a severe and unexpected downshift into first gear at highway speeds. Dashboard warning lights immediately illuminated, indicating multiple system faults. I was able to safely pull over and shift the vehicle into park. However, after doing so, the truck completely refused to engage drive or any other gear. This abrupt and uncommanded downshift posed a serious safety risk, not only to myself but to other drivers, due to the potential for loss of vehicle control. The vehicle had to be towed from the scene. It has now been at the dealership for over two and a half months, with no clear timeline for repair or resolution. This incident raises major concerns about the reliability and safety of the transmission system, particularly under high-speed conditions.