Diesel Data: Automotive Repair

Circuit Opening Relay

Circuit Opening Relay:






The Airflow Meter does not control fuel pump operation after start-up, so the ECU must keep the circuit open by sending a signal to the Circuit Opening Relay, located in the RH kick panel, near the ECU. As long as the ECU senses ignition pulses, the relay will allow current to flow to the fuel pump. The relay inputs ground to the ECU through terminal FC.