SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

When the engine is cranked, the starter relay drive signal output from the ignition switch*1 or power management control ECU*2 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 Tr1 in the ECM internal circuit on. The current flows to the C/OPN (Circuit Opening) relay by turning Tr1 on.

Then, the fuel pump operates.

While the NE signal is input into the ECM, when the engine is running, the ECM turns Tr1 on continuously.


A0053ORE07

WIRING DIAGRAM

A0052KKE11

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 (OPERATE C/OPN RELAY)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

    5. Check whether the fuel pump operation sound occurs when performing the Active Test on the GTS.

      OK
      Fuel pump operating sound occurs.

    OK

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

    NG

  2. INSPECT INSTRUMENT PANEL JUNCTION BLOCK (C/OPN RELAY)


    1. Inspect the C/OPN relay Click here.


    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK (C/OPN RELAY)

    OK

  3. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - ECM)


    1. Disconnect the ECM connector.

    2. Disconnect the instrument panel junction block connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      DB-10 - A67-41 (FC) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      DB-10 or A67-41 (FC) - Body ground Always 10 kΩ or higher

    4. Reconnect the ECM connector.

    5. Reconnect the instrument panel junction block connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (C/OPN RELAY - ECM)

    OK

  4. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - INTEGRATION RELAY (EFI MAIN RELAY, IG2 RELAY))


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

    2. Disconnect the integration relay connector.

    3. Disconnect the instrument panel junction block connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      DB-11 - 1B-4 Always Below 1 Ω
      DF-4 - 1A-4 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      DB-11 or 1B-4 - Body ground Always 10 kΩ or higher
      DF-4 or 1A-4 - Body ground Always 10 kΩ or higher

    5. Reconnect the instrument panel junction block connector.

    6. Reconnect the integration relay connector.

    7. Reinstall the integration relay.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (C/OPN RELAY - INTEGRATION RELAY (EFI MAIN RELAY, IG2 RELAY))

    OK

  5. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - FUEL PUMP)


    1. Disconnect the fuel pump connector.

    2. Disconnect the instrument panel junction block connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      DA-8 - G24-4 Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      DA-8 or G24-4 - Body ground Always 10 kΩ or higher

    4. Reconnect the instrument panel junction block connector.

    5. Reconnect the fuel pump connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (C/OPN RELAY - FUEL PUMP)

    OK

  6. 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 (Check for Open)
      Tester Connection Condition Specified Condition
      G24-5 - Body ground Always Below 1 Ω

    3. Reconnect the fuel pump connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (FUEL PUMP - BODY GROUND)

    OK

  7. 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

  8. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit Click here.


    OK

    REPLACE ECM Click here

    NG

    REPAIR ECM POWER SOURCE CIRCUIT