Circuit Opening Relay (4Runner)

Circuit opening relay controls fuel pump circuit. When EFI main relay is energized, it provides battery voltage to one side of circuit opening relay. When ignition is turned on, voltage is supplied through IGN fuse to other side of circuit opening relay. When proper input signals are delivered to Engine Control Module (ECM), circuit opening relay ground circuit is grounded at ECM terminal FC. Circuit opening relay then provides voltage to fuel pump through fuel pump relay for fuel pump operation. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION  table.