The contact owns a 2020 Chevrolet Silverado 2500. The contact stated that while driving 30-50 MPH on four occasions, the rear wheels locked up. There were no warning lights illuminated. The contact received notification of NHTSA Campaign Number: 24V797000 (Power Train); however, the part to do the recall repair was not yet available. The local dealer was contacted. The vehicle was taken to the local dealer, where it was diagnosed that a software update was needed. The vehicle was repaired, but the failure recurred. The vehicle was taken back to the local dealer, who was unable to duplicate the failure. The vehicle was not repaired. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The failure mileage was approximately 81,381. VIN tool confirms parts not available.