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.


A00DQOXE01

WIRING DIAGRAM

A00DSGME03

INSPECTION PROCEDURE

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (OPERATE C/OPN RELAY)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester 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 tester.

      OK
      Fuel pump operating sound occurs.

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


    1. A00DSSZE38
      Text in Illustration
      *1

      Component without harness connected

      (Instrument Panel Junction Block)

      Disconnect the instrument panel junction block connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      DA-8 - DB-11 Battery voltage is not applied to terminals DB-10 and DF-4 10 kΩ or higher
      Battery voltage is applied to terminals DB-10 and DF-4 Below 1 Ω
    3. Reconnect the instrument panel junction block connector.


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


    1. A00DU2NE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Instrument Panel Junction Block)

      *2 Instrument Panel Junction Block
      *3

      Front view of wire harness connector

      (to ECM)

      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 - A40-19 (FC) Always Below 1 Ω
      Standard Resistance (Check for short)
      Tester Connection Condition Specified Condition
      DB-10 or A40-19 (FC) - Body ground Always 10 kΩ or higher
    4. Reconnect the ECM connector.

    5. Reconnect the instrument panel junction block connector.


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


    1. A00DTIFE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Instrument Panel Junction Block)

      *2 Instrument Panel Junction Block
      *3 Engine Room No. 1 Relay Block
      *4

      Front view of wire harness connector

      (to Integration Relay)

      Remove the integration relay from 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
    OK
  5. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - FUEL PUMP)


    1. A00DRGVE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Instrument Panel Junction Block)

      *2 Instrument Panel Junction Block
      *3

      Front view of wire harness connector

      (to Fuel Pump)

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


    1. A00DSASE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Fuel Pump)

      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
      G24-5 - Body ground Always Below 1 Ω
    3. Reconnect the fuel pump connector.


    NG
    OK
  7. INSPECT FUEL PUMP


    1. Inspect the fuel pump Click here.


    NG
    OK
  8. CHECK ECM POWER SOURCE CIRCUIT


    1. Check the ECM power source circuit Click here.


    NG
    OK