SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

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

WIRING DIAGRAM

A0029EIE02

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. INSPECT FUEL PUMP CONTROL ECU

    A0029OJC19
    *1 Fuel Pump Control ECU - -

    1. Remove the fuel pump control ECU.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M47-1 (+B) - M47-3 (GND) Always 200 Ω or higher
      M47-1 (+B) - M47-2 (FPC) Always 2 kΩ or higher
      M47-2 (FPC) - M47-3 (GND) Always 10 kΩ or higher
      M46-1 (FPG) - M47-3 (GND) Always 1 kΩ or higher
      M46-2 (FPU) - M47-3 (GND) Always 2 kΩ or higher
      M46-3 (FPV) - M47-3 (GND) Always 2 kΩ or higher
      M46-4 (FPW) - M47-3 (GND) Always 2 kΩ or higher

      Tech Tips

      This procedure checks for an internal short of the fuel pump control ECU when its transistor is stuck on.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FUEL PUMP CONTROL ECU Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE OF FUEL PUMP CONTROL ECU)

    A002B07C24
    *a

    Front view of wire harness connector

    (to Fuel Pump Control ECU)

    1. Disconnect the fuel pump control ECU 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
      M47-1 (+B) - M47-3 (GND) Ignition switch ON 11 to 14 V

      Tech Tips

      Make a note of the measured voltage as it may be used in a following Active Test.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE OF FUEL PMP RELAY) Click here

    OK

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


    1. Disconnect the fuel pump control 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
      M47-2 (FPC) - A43-18 (FPC) Always Below 1 Ω
      M47-2 (FPC) or A43-18 (FPC) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. PERFORM ACTIVE TEST USING GTS (FUEL PUMP SINGLE PHASE ENERGIZATION)

    A002COLC19
    *1 Fuel Pump Control ECU - -

    1. Disconnect the M46 fuel pump control ECU 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 / Fuel Pump Single Phase Energization.


      Powertrain > Engine > Active Test
      Tester Display
      Fuel Pump Single Phase Energization

    6. Operate the fuel pump control ECU 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
      M46-2 (FPU) - Body ground U Phase 4.4 to 8.4 V*
      M46-3 (FPV) - Body ground V Phase 4.4 to 8.4 V*
      M46-4 (FPW) - Body ground W Phase 4.4 to 8.4 V*

      Tech Tips


      • *: This Active Test restricts the fuel pump control ECU output duty cycle to 50%. Therefore, the output voltage of the fuel pump control ECU will be approximately 50% of the power source voltage measured in a previous step.

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

      Result
      Result Proceed to
      The U phase, V phase and W phase are all normal A
      The U phase, V phase or W phase is abnormal B
      The U phase, V phase and W phase are all abnormal C

    B

    REPLACE FUEL PUMP CONTROL ECU Click here

    C

    INSPECT ECM (FPC TERMINAL) Click here

    A

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


    1. Disconnect the fuel pump control ECU connector.

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M46-2 (FPU) - M48-3 (BLPU) Always Below 1 Ω
      M46-3 (FPV) - M48-4 (BLPV) Always Below 1 Ω
      M46-4 (FPW) - M48-2 (BLPW) Always Below 1 Ω
      M46-2 (FPU) or M48-3 (BLPU) - Body ground and other terminals Always 10 kΩ or higher
      M46-3 (FPV) or M48-4 (BLPV) - Body ground and other terminals Always 10 kΩ or higher
      M46-4 (FPW) or M48-2 (BLPW) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

      Tech Tips

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

      Click here


    OK

    REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. INSPECT ECM (FPC TERMINAL)

    A002B07C25
    *a

    Front view of wire harness connector

    (to Fuel Pump Control ECU)

    1. Disconnect the fuel pump control ECU 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 / Fuel Pump Single Phase Energization.


      Powertrain > Engine > Active Test
      Tester Display
      Fuel Pump Single Phase Energization

    6. Operate the fuel pump control 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
      M47-2 (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 Click here

    NG

    REPLACE ECM Click here

  7. CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE OF FUEL PMP RELAY)


    1. Remove the FUEL PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      3 (FUEL PMP relay) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - FUEL PMP RELAY)

    OK

  8. INSPECT FUEL PMP RELAY


    1. Inspect the FUEL PMP relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE FUEL PMP RELAY

    OK

  9. CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - ECM)


    1. Disconnect the semiconductor pwr integration 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
      1G-6 - A43-46 (MREL) Always Below 1 Ω
      1G-6 or A43-46 (MREL) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - FUEL PMP RELAY)


    1. Disconnect the semiconductor pwr integration ECU connector.

    2. Remove the FUEL PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1G-8 - 2 (FUEL PMP relay) Always Below 1 Ω
      1G-8 or 2 (FUEL PMP relay) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK HARNESS AND CONNECTOR (FUEL PMP RELAY - BODY GROUND)


    1. Remove the FUEL PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (FUEL PMP relay) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK HARNESS AND CONNECTOR (FUEL PMP RELAY - FUEL PUMP CONTROL ECU)


    1. Remove the FUEL PMP relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. Disconnect the fuel pump control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      5 (FUEL PMP relay) - M47-1 (+B) Always Below 1 Ω
      5 (FUEL PMP relay) or M47-1 (+B) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the fuel pump control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      M47-3 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR