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



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.
      Result
      Result Proceed to
      NG A
      OK B

    NG

    INSPECT FUEL PUMP ECU (POWER SOURCE VOLTAGE) Click here

    OK

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

    B0019I7E01
    *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

    REPLACE FUEL PUMP ECU Click here

    OK

  3. 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 LHD
      Tester Connection Condition Specified Condition
      N12-5 (FPC) - A38-50 (FPC) Always Below 1 Ω
      N12-5 (FPC) or A38-50 (FPC) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      N12-5 (FPC) - A87-50 (FPC) Always Below 1 Ω
      N12-5 (FPC) or A87-50 (FPC) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE FUEL PUMP


    1. Replace the fuel pump Click here.

      Tech Tips

      Perform "Inspection After Repair" after replacing 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

    REPLACE ECM Click here

  6. REPLACE FUEL PUMP ECU


    1. Replace the fuel pump ECU Click here.


    NEXT

  7. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check the fuel pump operation.

      OK
      Malfunction has been repaired successfully.

    OK

    END

    NG

    REPLACE ECM Click here

  8. INSPECT FUEL PUMP ECU (POWER SOURCE VOLTAGE)

    B0019CIE01
    *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
      N12-6 (+B) - Body Ground Engine switch on (IG) 11 to 14 V

    NG

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

    OK

  9. 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) - N12-1 (FP) Always Below 1 Ω
      N1-5 (E2) - N12-2 (FP-) Always Below 1 Ω
      N1-4 (B2) or N12-1 (FP) - Body ground Always 10 kΩ or higher
      N1-5 (E2) or N12-2 (FP-) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. INSPECT FUEL PUMP


    1. Inspect the fuel pump Click here.

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump Click here.


    NG

    REPLACE FUEL PUMP Click here

    OK

  11. 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
      for LHD
      Tester Connection Condition Specified Condition
      A38-50 (FPC) - N12-5 (FPC) Always Below 1 Ω
      N12-3 (E) - Body ground Always Below 1 Ω
      A38-50 (FPC) or N12-5 (FPC) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      A87-50 (FPC) - N12-5 (FPC) Always Below 1 Ω
      N12-3 (E) - Body ground Always Below 1 Ω
      A87-50 (FPC) or N12-5 (FPC) - Body ground Always 10 kΩ or higher

    OK

    REPLACE FUEL PUMP ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  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 - N12-6 (+B) Always Below 1 Ω
      1R-6 or N12-6 (+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