EFI Main Relay (LX470)

EFI main relay may also be referred to as EFI relay or ECD relay. EFI fuse supplies constant battery voltage to one side of EFI main relay. EFI fuse may also be referred to as ECD fuse. When EFI main relay is energized by MREL terminal of Engine Control Module (ECM), EFI main relay provides battery voltage to +B terminal of fuel pump Electronic Control Unit (ECU) and various other electrical components. EFI main relay also provides battery voltage to +B and +B1 terminals of ECM. For operation of fuel pump ECU and fuel pump switch, see FUEL PUMP ELECTRONIC CONTROL UNIT (ECU) & FUEL PUMP SWITCH (LX470) . EFI main relay is located in fuse/relay box at driver's side front corner of engine compartment, near battery.