EFI Main Relay (Prius)

EFI main relay may also be referred to as EFI relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI main relay is energized by MREL terminal of Engine Control Module (ECM). When EFI main relay is energized, EFI main relay provides battery voltage to circuit opening relay, +B terminal of ECM and various other electrical components. For EFI main relay location, see EFI MAIN RELAY LOCATION  table.