SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

When the engine is cranked, current flows from terminal ST2 of the ignition switch to the starter relay (Marking: ST) coil, and current also flows to terminal STA of the ECM (STA signal).

When the STA signal and NE signal are transmitted to the ECM, the power transistor (Tr) is turned ON, current flows to the circuit opening relay (Marking: C/OPN) coil, the relay switches on, power is supplied to the fuel pump and the fuel pump operates.

While the NE signal is generated (when engine running), the ECM keeps Tr ON (circuit opening relay ON) and the fuel pump also keeps operating.

A01DXI1E01

WIRING DIAGRAM

A01DV2SE01

INSPECTION PROCEDURE

When using intelligent tester:

PROCEDURE


  1. PERFORM ACTIVE TEST (OPERATE C/OPN RELAY)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch ON and turn the intelligent tester ON.

    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Fuel Pump.

    4. Check the operation of the relay while operating it using the intelligent tester.

      OK
      Operating noise can be heard from the fuel pump.

    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

    NG

  2. CHECK ECM POWER SOURCE CIRCUIT


    1. Refer to ECM power source circuit Click here.


    NG

    REPAIR OR REPLACE POWER SOURCE CIRCUIT

    OK

  3. CHECK ECM (FC VOLTAGE)

    A01DYCSE23

    1. Turn the ignition switch ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      E9-25 (FC) - E12-3 (E1) 9 to 14 V

    NG

    CHECK WIRE HARNESS (INTEGRATION RELAY (C/OPN RELAY) - ECM) Click here

    OK

  4. CHECK INTEGRATION NO.1 RELAY (C/OPN RELAY)

    A01DZ2WE03

    1. Remove the integration relay from the engine room junction block Click here.

    2. Measure the voltage of the C/OPN relay.

      Standard voltage
      Tester Connection Condition Specified Condition
      1J-8 - Body ground Engine cranking 10 to 14 V

    NG

    REPLACE INTEGRATION NO.1 RELAY

    OK

  5. INSPECT FUEL PUMP


    1. Inspect the fuel pump Click here.


    NG

    REPLACE FUEL PUMP

    OK

  6. CHECK WIRE HARNESS (FUEL PUMP - INTEGRATION RELAY (C/OPN RELAY), BODY GROUND)

    A01DX29E01

    1. Disconnect the 1J integration relay connector from the engine room junction block Click here.

    2. Disconnect the F15 fuel pump connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      1J-8 - F15-4 Below 1 Ω
      F15-5 - Body ground Below 1 Ω
      1J-8 or F15-4 - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM

  7. CHECK WIRE HARNESS (INTEGRATION RELAY (C/OPN RELAY) - ECM)

    A01DVFHE02

    1. Disconnect the 1J integration relay connector from the engine room junction block Click here.

    2. Disconnect the E9 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      1J-7 - E9-25 (FC) Below 1 Ω
      1J-7 or E9-25 (FC) - Body ground 10 kΩ or higher

    4. Turn the ignition switch ON.

    5. Measure the voltage of the C/OPN relay.

      Standard voltage
      Tester Connection Specified Condition
      1J-6 - Body ground 9 to 14 V

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM

When not using intelligent tester:

PROCEDURE


  1. INSPECT FUEL PUMP (OPERATION)


    1. Operation of fuel pump Click here.


    OK

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

    NG

  2. CHECK ECM POWER SOURCE CIRCUIT


    1. Refer to ECM power source circuit Click here.


    NG

    REPAIR OR REPLACE POWER SOURCE CIRCUIT

    OK

  3. CHECK ECM (FC VOLTAGE)

    A01DYCSE23

    1. Turn the ignition switch ON.

    2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition
      E9-25 (FC) - E12-3 (E1) 9 to 14 V

    NG

    CHECK WIRE HARNESS (INTEGRATION RELAY (C/OPN RELAY) - ECM) Click here

    OK

  4. CHECK INTEGRATION NO.1 RELAY (C/OPN RELAY)

    A01DZ2WE03

    1. Remove the integration relay from the engine room junction block Click here.

    2. Measure the voltage of the C/OPN relay.

      Standard voltage
      Tester Connection Condition Specified Condition
      1J-8 - Body ground Engine cranking 10 to 14 V

    NG

    REPLACE INTEGRATION NO.1 RELAY

    OK

  5. INSPECT FUEL PUMP


    1. Inspect the fuel pump Click here.


    NG

    REPLACE FUEL PUMP

    OK

  6. CHECK WIRE HARNESS (FUEL PUMP - INTEGRATION RELAY (C/OPN RELAY), BODY GROUND)

    A01DX29E01

    1. Disconnect the 1J integration relay connector from the engine room junction block Click here.

    2. Disconnect the F15 fuel pump connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      1J-8 - F15-4 Below 1 Ω
      F15-5 - Body ground Below 1 Ω
      1J-8 or F15-4 - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM

  7. CHECK WIRE HARNESS (INTEGRATION RELAY (C/OPN RELAY) - ECM)

    A01DVFHE02

    1. Disconnect the 1J integration relay connector from the engine room junction block Click here.

    2. Disconnect the E9 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition
      1J-7 - E9-25 (FC) Below 1 Ω
      1J-7 or E9-25 (FC) - Body ground 10 kΩ or higher

    4. Turn the ignition switch ON.

    5. Measure the voltage of the C/OPN relay.

      Standard voltage
      Tester Connection Specified Condition
      1J-6 - Body ground 9 to 14 V

    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

    REPLACE ECM