The contact owns a 2016 BMW X5. The contact stated that while driving at an undisclosed speed, the transmission unexpectedly downshifted, and the contact discovered an unknown liquid leaking underneath of the vehicle. The check engine warning light was illuminated. The contact received notification of NHTSA Campaign Number: 24V608000 (Engine and Engine Cooling; Electrical System); however, the part to do the recall repair was not yet available. The local dealer was contacted however, the vehicle was not diagnosed. 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 120,000. VIN tool confirms parts not available.