The contact owns a 2018 Ram 3500. The contact stated that while driving at an undisclosed speed, the ABS warning light illuminated. The vehicle was taken to the dealer where it was diagnosed with a failed hydraulic control unit. The contact was informed that the hydraulic control unit needed to be replaced. The vehicle was not repaired. The contact was informed that the parts were not yet available. The contact received notification of NHTSA Campaign Number: 21V398000 (Wheels); however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the failure. The failure mileage was unknown. Parts distribution disconnect.