SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

The fuel pump circuit consists of the ECM, fuel pump and fuel pump ECU (which operates the fuel pump). Based on the engine output, the ECM determines the fuel pump speed. The speed is then converted to a duty signal and sent to the fuel pump ECU. Based on the signal sent from the ECM, the fuel pump ECU adjusts the fuel pump operation speed among 3 settings.

WIRING DIAGRAM

Refer to DTC P0230 Click here.

INSPECTION PROCEDURE

This troubleshooting procedure is based on the premise that the engine is started. If the engine is not started, proceed to Problem Symptoms Table Click here.

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FUEL PUMP)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and turn the tester on.

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

    4. Check whether operating sounds can be heard while operating the relay using the tester.

      OK
      Operating sounds can be heard from relay.

    NG

    Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM, BODY GROUND)


    1. Disconnect the fuel pump ECU connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      S8-1 (FPC) - G55-3 (FPC) Always Below 1 Ω
      S8-2 (DI) - G56-26 (DI) Always Below 1 Ω
      S8-3 (E) - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      S9-2 (FP-) - Body ground Always 10 kΩ or higher
      S8-1 (FPC) or G55-3 (FPC) - Body ground Always 10 kΩ or higher
      S8-2 (DI) or G56-26 (DI) - Body ground Always 10 kΩ or higher

    4. Reconnect the fuel pump ECU connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. REPLACE FUEL PUMP ECU


    1. Replace the fuel pump ECU Click here.


    NEXT

  4. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check the fuel pump operation.

      OK
      Malfunction has been repaired successfully.

    NG

    REPLACE ECM Click here

    OK

    END

  5. INSPECT CIRCUIT OPENING RELAY (C/OPN)


    1. Inspect the circuit opening relay (C/OPN) Click here.


    NG

    REPLACE CIRCUIT OPENING RELAY (C/OPN)

    OK

  6. INSPECT CIRCUIT OPENING RELAY (C/OPN) (POWER SOURCE VOLTAGE)

    A01DU2HE02
    Text in Illustration
    *1 Engine Room Relay Block
    *2 Circuit Opening Relay (C/OPN)

    1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      C/OPN relay terminal 2 - Body ground Ignition switch ON 11 to 14 V
      C/OPN relay terminal 5 - Body ground Ignition switch ON 11 to 14 V

    3. Reinstall the circuit opening relay (C/OPN).


    NG

    Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - ECU, FUEL PUMP ECU)


    1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

    2. Disconnect the fuel pump ECU connector.

    3. Disconnect the ECM connector.

    4. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C/OPN relay terminal 1 - G56-8(FC) Always Below 1 Ω
      C/OPN relay terminal 3 - S8-4 (+B) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C/OPN relay terminal 1 or G56-8 (FC) - Body ground Always 10 kΩ or higher
      C/OPN relay terminal 3 or S8-4 (+B) - Body ground Always 10 kΩ or higher

    5. Reinstall the circuit opening relay (C/OPN).

    6. Reconnect the fuel pump ECU connector.

    7. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP ECU)


    1. Disconnect the fuel sender gauge connector.

    2. Disconnect the fuel pump ECU connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      S5-4 (B2) - S9-1 (FP) Always Below 1 Ω
      S5-5 (E2) - S9-2 (FP-) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      S5-4 (B2) or S9-1 (FP) - Body ground Always 10 kΩ or higher
      S5-5 (E2) or S9-2 (FP-) - Body ground Always 10 kΩ or higher

    4. Reconnect the fuel sender gauge connector.

    5. Reconnect the fuel pump ECU connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. INSPECT FUEL PUMP


    1. Inspect the fuel pump (for Single Tank Type) Click here.

    2. Inspect the fuel pump (for Double Tank Type) Click here.

      Result
      Test Result Proceed to
      OK A
      NG (for Single Tank Type) B
      NG (for Double Tank Type) C

    B

    REPLACE FUEL PUMP Click here

    C

    REPLACE FUEL PUMP Click here

    A

  10. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM, BODY GROUND)


    1. Disconnect the fuel pump ECU connector.

    2. Disconnect the ECM connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      S8-1 (FPC) - G55-3 (FPC) Always Below 1 Ω
      S8-2 (DI) - G56-26 (DI) Always Below 1 Ω
      S8-3 (E) - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      S8-1 (FPC) or G55-3 (FPC) - Body ground Always 10 kΩ or higher
      S8-2 (DI) or G56-26 (DI) - Body ground Always 10 kΩ or higher

    4. Reconnect the fuel pump ECU connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. REPLACE FUEL PUMP ECU


    1. Replace the fuel pump ECU Click here.


    NEXT

  12. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check the fuel pump operation.

      OK
      Malfunction has been repaired successfully.

    NG

    REPLACE ECM Click here

    OK

    END

  13. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - IGN FUSE, NO. 1 INTEGRATION RELAY)


    1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

    2. Remove the No. 1 integration relay from the engine room relay block.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      C/OPN relay terminal 2 - 1A-5 Always Below 1 Ω
      C/OPN relay terminal 5 - 1B-4 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C/OPN relay terminal 2 or 1A-5 - Body ground Always 10 kΩ or more
      C/OPN relay terminal 5 or 1B-4 - Body ground Always 10 kΩ or more

    4. Reinstall the circuit opening relay (C/OPN).

    5. Reinstall the No. 1 integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here