EFI Main Relay

The EFI fuse supplies constant battery voltage to EFI main relay. When EFI main relay is energized by ignition switch, EFI main relay provides battery voltage to circuit opening relay (some models), data link connector No. 1 and various other electrical components. The EFI main relay may also provide battery voltage to +B terminal of ECM when ignition is turned on. The EFI main relay is located in engine compartment relay box.