The contact’s sister owns a 2020 Cadillac CT5. The contact stated that while his sister was driving at an undisclosed speed, the rear wheels locked up. The driver was able to pull over to the side of the road. The vehicle was towed to the dealer, where it was diagnosed and determined that the rear wheels had locked up, causing damages to the transmission. The dealer determined that the transmission needed to be replaced but at the vehicle owner’s expense. The vehicle was not repaired. The contact became aware that the VIN was included in NHTSA Campaign Number: 25V148000 (Power Train), which the contact related to the failure; however, the contact’s sister had not received the recall notification in the mail. The manufacturer was notified of the failure, but no assistance was provided. The failure mileage was unknown.