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

A01FIZCE01

INSPECTION PROCEDURE

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

    INSPECT FUEL PUMP ECU (POWER SOURCE VOLTAGE) Click here

    OK

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

    A01FFOZE02
    Text in Illustration
    *a

    Component with harness connected

    (Fuel Pump)

    1. Remove the fuel tank assembly

      Tech Tips


    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:

      Make sure that there is no fuel remaining 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 GTS 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 GTS 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 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
      Tester Connection Condition Specified Condition
      U38-5 (FPC) - A19-5 (FPC) Always Below 1 Ω
      U38-5 (FPC) or A19-5 (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.


    NEXT

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED Click here

  5. REPLACE FUEL PUMP ECU


    1. Replace the fuel pump ECU Click here.


    NEXT

  6. 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

  7. INSPECT FUEL PUMP ECU (POWER SOURCE VOLTAGE)

    A01FFL2E07
    Text in Illustration
    *a

    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
      U38-6 (+B) - Body Ground Engine switch on (IG) 11 to 14 V

    NG

    INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN2) Click here

    OK

  8. 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
      U38-3 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    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
      U11-4 (B) - U38-1 (FP) Always Below 1 Ω
      U11-5 (E) - U38-2 (FP-) Always Below 1 Ω
      U11-4 (B) or U38-1 (FP) - Body ground Always 10 kΩ or higher
      U11-5 (E) or U38-2 (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.


    NG

    REPLACE FUEL PUMP Click here

    OK

  11. 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
      Tester Connection Condition Specified Condition
      U38-5 (FPC) - A19-5 (FPC) Always Below 1 Ω
      U38-5 (FPC) or A19-5 (FPC) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. REPLACE FUEL PUMP ECU


    1. Replace the fuel pump ECU Click here.


    NEXT

  13. 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

  14. INSPECT NO. 1 INTEGRATION RELAY (EFI MAIN2)


    1. Inspect the No. 1 integration relay (EFI MAIN2) Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY

    OK

  15. CHECK HARNESS AND CONNECTOR (NO. 2 ENGINE ROOM RELAY BLOCK ASSEMBLY - FUEL PUMP ECU)


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

    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
      2F-12 - U38-6 (+B) Always Below 1 Ω
      2F-12 or U38-6 (+B) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here