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.

WIRING DIAGRAM

B001WRPE01

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP / SPEED)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the GTS on.

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

    5. Check whether operating sounds can be heard while operating the fuel pump using the GTS.

      OK
      Operating sounds can be heard from fuel pump.

    NG

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

    OK

  2. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP DUTY)

    B001WWQE01
    *a Component with harness connected: (Fuel Pump)

    1. Remove the fuel tank assembly Click here.

    2. Remove the fuel pump from the fuel tank assembly.

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

    4. Connect the fuel pump connector.

      CAUTION:

      Confirm that no fuel remains inside or on the outside of the fuel pump.

    5. Connect the GTS to the DLC3.

    6. Turn the engine switch on (IG).

    7. Turn the GTS on.

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

    9. Operate the fuel pump using the Active Test function and measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Tester Operation Specified Condition
      1 - 2 FPC Duty: 25% 3.2 to 4.05 V
      FPC Duty: 80% 8.8 to 12.5 V

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

    11. Operate the fuel pump using the Active Test function and measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Tester Operation Specified Condition
      1 - 2 ON (FPC Duty: 90%) 9.0 to 14.0 V

      Tech Tips


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

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


    NG

    INSPECT FUEL PUMP Click here

    OK

  3. INSPECT FUEL PUMP


    1. Inspect the fuel pump Click here.


    OK

    END

    NG

  4. REPLACE FUEL PUMP


    1. Replace the fuel pump Click here.


    NEXT

  5. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check the fuel pump operation.

      OK
      Malfunction has been repaired successfully.

    OK

    END

    NG

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

  6. CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL PUMP ECU)

    B001VQTC01
    *1

    Front view of wire harness connector

    (to Fuel Pump ECU)

    1. Disconnect the fuel pump ECU connector.

    2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      N14-6 (+B) - N14-3 (E) Engine switch on (IG) 11 to 14 V

    NG

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

    OK

  7. INSPECT FUEL PUMP


    1. Inspect the fuel pump Click here.


    NG

    REPLACE FUEL PUMP Click here

    OK

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


    1. Disconnect the fuel pump connector.

    2. Disconnect the fuel pump ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N1-4 (B2) - N14-1 (FP) Always Below 1 Ω
      N1-5 (E2) - N14-2 (FP-) Always Below 1 Ω
      N1-4 (B2) or N14-1 (FP) - Body ground Always 10 kΩ or higher
      N1-5 (E2) or N14-2 (FP-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM)


    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 (for RHD)
      Tester Connection Condition Specified Condition
      N14-5 (FPC) - A52-52 (FPC) Always Below 1 Ω
      N14-5 (FPC) or A52-52 (FPC) - Body ground Always 10 kΩ or higher
      Standard Resistance (for LHD)
      Tester Connection Condition Specified Condition
      N14-5 (FPC) - A38-52 (FPC) Always Below 1 Ω
      N14-5 (FPC) or A38-52 (FPC) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. INSPECT ECM (FPC TERMINAL)


    1. B001VQTC02
      *1

      Front view of wire harness connector

      (to Fuel Pump ECU)

      Disconnect the fuel pump ECU connector.

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

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

    6. Operate the fuel pump ECU 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
      N14-5 (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.


    OK

    REPLACE FUEL PUMP ECU

    NG

    REPLACE ECM Click here

  11. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - BODY GROUND)


    1. Disconnect the fuel pump ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      N14-3 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY - FUEL PUMP ECU)


    1. Disconnect the fuel pump ECU connector.

    2. Disconnect the No. 2 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1R-6 - N14-6 (+B) Always Below 1 Ω
      1R-6 or N14-6 (+B) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  13. INSPECT NO. 2 INTEGRATION RELAY (FUEL PMP)


    1. Inspect the No. 2 integration relay (FUEL PMP) Click here.


    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here

    NG

    REPLACE NO. 2 INTEGRATION RELAY