Circuit Opening Relay (Sequoia)

Circuit opening relay controls fuel pump circuit by supplying voltage to fuel pump relay. When EFI main relay is energized, EFI main relay provides battery voltage to one side of circuit opening relay. When ignition is turned on, voltage is supplied through IGN No. 1 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 relay which supplies voltage to fuel pump for fuel pump operation. For circuit opening relay location, see CIRCUIT OPENING RELAY LOCATION  table. For operation of fuel pump relay, see FUEL PUMP RELAY & FUEL PUMP RESISTOR  under FUEL PUMP CONTROL CIRCUIT.