SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

When the engine is cranked, the starter (ST NO. 1) relay drive signal output from the certification ECU (smart key ECU assembly) is input into the STA terminal of the ECM, and the NE signal generated by the crankshaft position sensor is also input into the NE+ terminal. The ECM interprets that the engine is cranked, and turns transistor in the ECM internal circuit on. Current flows to the C/OPEN relay by turning transistor on. Then, the fuel pump operates.

While the NE signal is input into the ECM with the engine running, the ECM turns transistor on continuously.

WIRING DIAGRAM

B006QOOE01

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 (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.


      Powertrain > Engine > Active Test
      Tester Display
      Control the Fuel Pump / Speed

    5. Check whether the fuel pump operating sounds occurs when performing the Active Test on the GTS.

      Result
      Result Proceed to
      Fuel pump operating sound does not occur A
      Fuel pump operating sound occurs B

    B

    READ VALUE USING GTS (STARTER SIGNAL) Click here

    A

  2. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY POWER SOURCE)


    1. Disconnect the No. 1 integration relay connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1A-1 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - NO. 1 INTEGRATION RELAY)

    OK

  3. INSPECT NO. 1 INTEGRATION RELAY


    1. Inspect the No. 1 integration relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY)


    1. Disconnect the No. 1 integration relay connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1E-3 - 1D-6 Always Below 1 Ω
      1E-3 or 1D-6 - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM)


    1. Disconnect the No. 1 integration relay 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
      1E-12 - A53-41 (FC) Always Below 1 Ω
      1E-12 or A53-41 (FC) - Body ground and other terminals Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - FUEL PUMP)


    1. Disconnect the No. 1 integration relay connector.

    2. Disconnect the fuel pump connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1D-5 - K25-4 Always Below 1 Ω
      1D-5 or K25-4 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the fuel pump connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      K25-5 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. INSPECT FUEL PUMP


    1. Inspect the fuel pump.

      Click here

      Tech Tips

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

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPLACE FUEL PUMP Click here

  9. READ VALUE USING GTS (STARTER SIGNAL)


    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 / Data List / All Data / Starter Signal.


      Powertrain > Engine > Data List
      Tester Display
      Starter Signal

    5. Check the result when the engine switch is on (IG) and the engine starts.

      OK
      Condition Starter Signal
      Engine switch on (IG) OFF
      Engine started ON
      Result
      Proceed to
      OK
      NG

    NG

    CHECK STARTER SIGNAL CIRCUIT Click here

    OK

  10. READ VALUE USING GTS (ENGINE 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 / Data List / All Data / Engine Speed.


      Powertrain > Engine > Data List
      Tester Display
      Engine Speed

    5. Read the values displayed on the GTS while cranking.

      OK
      Values are displayed continuously.
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    CHECK CRANKSHAFT POSITION SENSOR CIRCUIT Click here