EFI Main Relay (4Runner)

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, data link connector No. 1 and various other electrical components. EFI main relay and EFI fuse are located in fuse/relay box at driver's side front corner of engine compartment, next to battery.