SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

The fuel pump circuit consists of the ECM, fuel pump (for low pressure side) and fuel pump control ECU assembly (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 control ECU assembly. Based on the signal sent from the ECM, the fuel pump control ECU adjust the fuel pump operation speed.

WIRING DIAGRAM

A005OLFE03

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (ACTIVATE THE CIRCUIT RELAY)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Engine / Active Test / Activate the Circuit Relay.


      Powertrain > Engine > Active Test
      Tester Display
      Activate the Circuit Relay

    5. Check whether operating sounds can be heard while operating the fuel pump (for low pressure side) using the GTS.

      OK
      Operating sounds can be heard from the fuel pump (for low pressure side).
      Result
      Proceed to
      OK
      NG

    NG

    CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL PUMP CONTROL ECU ASSEMBLY) Click here

    OK

  2. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP DUTY RATIO, ACTIVATE THE CIRCUIT RELAY)

    A005QCNC01
    *a

    Component with harness connected

    (Fuel Pump [for Low Pressure Side])

    1. Remove the fuel pump (for low pressure side) from the fuel tank assembly.

      for 2WD: Click here

      for AWD: Click here

    2. Clean the fuel pump to completely remove any remaining fuel.

    3. Connect the fuel pump connector.

      CAUTION:

      Make sure that there is no fuel remaining inside or on the outside of the fuel pump.

    4. Connect the GTS to the DLC3.

    5. Turn the ignition switch to ON.

    6. Turn the GTS on.

    7. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump Duty Ratio.


      Powertrain > Engine > Active Test
      Tester Display
      Control the Fuel Pump Duty Ratio

    8. Operate the fuel pump (for low pressure side) using the Active Test function and measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection GTS Operation Specified Condition
      2 - 1 Fuel pump duty ratio: 25% 3.2 to 4.05 V
      Fuel pump duty ratio: 80% 8.8 to 12.5 V

    9. Enter the following menus: Powertrain / Engine / Active Test / Activate the Circuit Relay.


      Powertrain > Engine > Active Test
      Tester Display
      Activate the Circuit Relay

    10. Operate the fuel pump (for low pressure side) using the Active Test function and measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection GTS Operation Specified Condition
      2 - 1 ON (Fuel pump duty ratio: 90%) 9.0 to 14.0 V

      Tech Tips


      • Be sure to measure the voltage with all the connectors connected.

      • Before performing this inspection, check that the battery voltage is between 11 and 14 V (not depleted).

      Result
      Result Proceed to
      OK (for 2WD) A
      OK (for AWD) B
      NG (for 2WD) C
      NG (for AWD) D

    B

    INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE) Click here

    C

    GO TO STEP 10 Click here

    D

    GO TO STEP 14 Click here

    A

  3. INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE)


    1. Inspect the fuel pump (for low pressure side).

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

  4. REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE)


    1. Replace the fuel pump (for low pressure side).

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check the fuel pump operation.

      Click here

      OK
      Malfunction has been repaired successfully.
      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  6. INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE)


    1. Inspect the fuel pump (for low pressure side).

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

  7. REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE)


    1. Replace the fuel pump (for low pressure side).

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  8. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check the fuel pump operation.

      Click here

      OK
      Malfunction has been repaired successfully.
      Result
      Proceed to
      OK
      NG

    OK

    END

    NG

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  9. CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL PUMP CONTROL ECU ASSEMBLY)

    A005PALC12
    *a

    Front view of wire harness connector

    (to Fuel Pump Control ECU Assembly)

    1. Disconnect the fuel pump control ECU assembly connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      M68-1 (+B) - M68-4 (E) Ignition switch ON 11 to 14 V
      Result
      Result Proceed to
      OK (for 2WD) A
      OK (for 2WD) B
      NG C

    B

    INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE) Click here

    C

    CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - BODY GROUND) Click here

    A

  10. INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE)


    1. Inspect the fuel pump (for low pressure side).

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here

    OK

  11. CHECK HARNESS AND CONNECTOR (FUEL PUMP (FOR LOW PRESSURE SIDE) - FUEL PUMP CONTROL ECU ASSEMBLY)


    1. Disconnect the M14 fuel pump (for low pressure side) connector.

    2. Disconnect the M68 fuel pump control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M14-4 (B) - M68-6 (FP) Always Below 1 Ω
      M14-5 (E) - M68-5 (FP-) Always Below 1 Ω
      M14-4 (B) - M68-6 (FP) - Body ground and other terminals Always 10 kΩ or higher
      M14-5 (E) - M68-5 (FP-) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - ECM)


    1. Disconnect the M68 fuel pump control ECU assembly connector.

    2. Disconnect the A38 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M68-2 (FPC) - A38-21 (FPC) Always Below 1 Ω
      M68-2 (FPC) or A38-21 (FPC) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP DUTY RATIO (INSPECT ECM))

    A005PF6C23
    *a

    Front view of wire harness connector

    (to Fuel Pump Control ECU Assembly)

    1. Disconnect the fuel pump control ECU assembly connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump Duty Ratio.


      Powertrain > Engine > Active Test
      Tester Display
      Control the Fuel Pump Duty Ratio

    6. Operate the fuel pump control ECU assembly using the Active Test function and measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection GTS Operation Specified Condition
      M68-2 (FPC) - Body ground Before Active Test → During Active Test Before Active Test: Resistance is stable → During Active Test: Resistance fluctuates*

      Tech Tips

      *: Using the Active Test, duty control of the transistors in the ECM will be performed. Due to the duty control, resistance of the FPC terminal will be unstable during the Active Test. If the resistance is stable before the Active Test and fluctuates while performing the Active Test, it can be determined that the transistor is operating. If the transistor does not operate during the Active Test, the ECM may be malfunctioning.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FUEL PUMP CONTROL ECU ASSEMBLY

    NG

    REPLACE ECM Click here

  14. INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE)


    1. Inspect the fuel pump (for low pressure side).

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump (for low pressure side).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here

    OK

  15. CHECK HARNESS AND CONNECTOR (FUEL PUMP (FOR LOW PRESSURE SIDE) - FUEL PUMP CONTROL ECU ASSEMBLY)


    1. Disconnect the M75 fuel pump (for low pressure side) connector.

    2. Disconnect the M68 fuel pump control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M75-4 (B) - M68-6 (FP) Always Below 1 Ω
      M75-5 (E) - M68-5 (FP-) Always Below 1 Ω
      M75-4 (B) - M68-6 (FP) - Body ground and other terminals Always 10 kΩ or higher
      M75-5 (E) - M68-5 (FP-) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  16. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - ECM)


    1. Disconnect the M68 fuel pump control ECU assembly connector.

    2. Disconnect the A38 ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M68-2 (FPC) - A38-21 (FPC) Always Below 1 Ω
      M68-2 (FPC) or A38-21 (FPC) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  17. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP DUTY RATIO (INSPECT ECM))

    A005PF6C24
    *a

    Front view of wire harness connector

    (to Fuel Pump Control ECU Assembly)

    1. Disconnect the fuel pump control ECU assembly connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump Duty Ratio.


      Powertrain > Engine > Active Test
      Tester Display
      Control the Fuel Pump Duty Ratio

    6. Operate the fuel pump control ECU assembly using the Active Test function and measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection GTS Operation Specified Condition
      M68-2 (FPC) - Body ground Before Active Test → During Active Test Before Active Test: Resistance is stable → During Active Test: Resistance fluctuates*

      Tech Tips

      *: Using the Active Test, duty control of the transistors in the ECM will be performed. Due to the duty control, resistance of the FPC terminal will be unstable during the Active Test. If the resistance is stable before the Active Test and fluctuates while performing the Active Test, it can be determined that the transistor is operating. If the transistor does not operate during the Active Test, the ECM may be malfunctioning.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FUEL PUMP CONTROL ECU ASSEMBLY

    NG

    REPLACE ECM Click here

  18. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - BODY GROUND)


    1. Disconnect the M68 fuel pump control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M68-4 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  19. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO.2 RELAY - FUEL PUMP CONTROL ECU ASSEMBLY)


    1. Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

    2. Disconnect the M68 fuel pump control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (EFI-MAIN NO. 2 relay holder) - M68-1 (+B) Always Below 1 Ω
      3 (EFI-MAIN NO. 2 relay holder) or M68-1 (+B) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  20. CHECK TERMINAL VOLTAGE (EFI-MAIN NO. 2 RELAY VOLTAGE)


    1. A005P66C01
      *1 No.1 Engine Room Relay Block
      *2 EFI-MAIN NO.2 Relay Holder

      Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      5 (EFI-MAIN NO. 2 relay holder) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI-MAIN NO. 2 RELAY)

    OK

  21. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 2 RELAY - BODY GROUND)


    1. A005P66C01
      *1 No.1 Engine Room Relay Block
      *2 EFI-MAIN NO.2 Relay Holder

      Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2 (EFI-MAIN NO. 2 relay holder) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  22. INSPECT EFI-MAIN NO. 2 RELAY


    1. Inspect the EFI-MAIN NO. 2 relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EFI-MAIN NO. 2 RELAY

    OK

  23. CHECK HARNESS AND CONNECTOR (NO.1 INTEGRATION RELAY - EFI-MAIN NO. 2 RELAY)


    1. Disconnect the 1B No.1 integration relay connector.

    2. Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1B-4 - 1 (EFI-MAIN NO. 2 relay holder) Always Below 1 Ω
      1B-4 or 1 (EFI-MAIN NO. 2 relay holder) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    CHECK ECM POWER SOURCE CIRCUIT Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR