EFI Main Relay

The No. 1 EFI fuse supplies constant battery voltage to EFI main relay, located in engine compartment relay box at driver's side front strut tower. The EFI main relay is turned on by M-REL terminal of Engine Control Module (ECM). When EFI main relay is turned on, voltage is supplied to +B terminal of ECM, data link connector No. 1, +B terminal of fuel pump Electronic Control Unit (ECU) and various other electrical components. Fuel pump ECU is located in driver's side rear corner of trunk. The ECM provides signals to fuel pump ECU for controlling fuel pump operation. Fuel pump ECU then provides voltage to the fuel pump.