TECHNICAL SERVICE BULLETIN: IBAU SYSTEM REPAIR FOR NOISE AND AIR BLEEDING - This bulletin has been revised to include additional information. This bulletin provides the repair procedure for the Integrated Brake Actuation Unit (iBAU) system on some 2014-2019MY EV/Hybrid/Plug-In Hybrid vehicles listed (see table), which may exhibit a “Honking†(Hissing) noise due to air remaining in the brake fluid system.