The contact owns a 2021 GMC Sierra 1500. The contact stated that the tailgate opened unintendedly while driving, and while the vehicle was parked. The contact stated that the failure had been recurring. The vehicle was taken to the dealer but was not diagnosed or repaired. The contact related the failure to GM Campaign Number: N232426400. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was approximately 76,000.