The contact owns a 2024 GMC Sierra 3500. The contact stated that while driving at 30 MPH, there was a loud pop and the vehicle jolted, after which the vehicle started to lose motive power. The contact was able to pull over to the shoulder of the roadway, where the failure persisted. The check engine warning light was illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the transmission valve body. The vehicle was not repaired due to a lack of parts availability. The manufacturer was notified of the failure, a case was opened, and the contact was referred to the NHTSA Hotline for assistance. The failure mileage was 63,000.