The contact owns a 2019 Cadillac CT6. The contact received notification of NHTSA Campaign Number: 25V148000 (Power Train); however, the part to do the recall repair was unavailable. The local dealer was contacted, and it was confirmed that the part was not yet available. 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. While driving approximately 70 MPH, the wheels locked up, causing the vehicle to lose automotive power and decelerate. The vehicle was driven to the local dealer who diagnosed that the transmission had failed and needed to be replaced. The vehicle was not repaired. The failure mileage was 84,000. VIN tool confirms parts not available.