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 among 3 settings.

WIRING DIAGRAM

Refer to DTC P0230 Click here.

CAUTION / NOTICE / HINT

This troubleshooting procedure is based on the premise that the engine is started. If the engine is not started, proceed to Problem Symptoms Table Click here.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (FUEL PUMP)


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) and turn the GTS on.

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

    4. Check whether the fuel pump operating sound occurs when performing the Active Test on the GTS.

      OK
      Operating sounds can be heard from fuel pump.

    OK

    PROCEED TO PROBLEM SYMPTOMS TABLE Click here

    NG

  2. INSPECT NO. 1 INTEGRATION RELAY (C/OPN RELAY)


    1. Inspect the NO. 1 integration relay (C/OPN relay) Click here.


    NG

    REPLACE NO. 1 INTEGRATION RELAY

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - ECM, FUEL PUMP ECU)


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

    2. Disconnect the fuel pump ECU connector.

    3. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open)
      for Automatic Transmission
      Tester Connection Condition Specified Condition
      1V-7 - G55-5(FC) Always Below 1 Ω
      1V-6 - S8-4 (+B) Always Below 1 Ω
      1V-1 - 1W-12 Always Below 1 Ω
      for Manual Transmission
      Tester Connection Condition Specified Condition
      1V-7 - G56-8(FC) Always Below 1 Ω
      1V-6 - S8-4 (+B) Always Below 1 Ω
      1V-1 - 1W-12 Always Below 1 Ω
      Standard Resistance (Check for Short)
      for Automatic Transmission
      Tester Connection Condition Specified Condition
      1V-7 or G55-5 (FC) - Body ground Always 10 kΩ or higher
      1V-6 or S8-4 (+B) - Body ground Always 10 kΩ or higher
      1V-1 or 1W-12 - Body ground Always 10 kΩ or higher
      for Manual Transmission
      Tester Connection Condition Specified Condition
      1V-7 or G56-8 (FC) - Body ground Always 10 kΩ or higher
      1V-6 or S8-4 (+B) - Body ground Always 10 kΩ or higher
      1V-1 or 1W-12 - Body ground Always 10 kΩ or higher

    5. Reinstall the No. 1 integration relay.

    6. Reconnect the fuel pump ECU connector.

    7. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP ECU)


    1. Disconnect the fuel sender gauge connector.

    2. Disconnect the fuel pump ECU connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      S5-4 (B2) - S9-1 (FP) Always Below 1 Ω
      S5-5 (E2) - S9-2 (FP-) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      S5-4 (B2) or S9-1 (FP) - Body ground Always 10 kΩ or higher
      S5-5 (E2) or S9-2 (FP-) - Body ground Always 10 kΩ or higher

    4. Reconnect the fuel sender gauge connector.

    5. Reconnect the fuel pump ECU connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT FUEL PUMP


    1. Inspect the fuel pump (for Single Tank Type) Click here.

    2. Inspect the fuel pump (for Double Tank Type) Click here.

      Result
      Test Result Proceed to
      OK A
      NG (for Single Tank Type) B
      NG (for Double Tank Type) C

      Tech Tips

      for Automatic Transmission

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


    B

    REPLACE FUEL PUMP Click here

    C

    REPLACE FUEL PUMP Click here

    A

  6. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM, BODY GROUND)


    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 (Check for Open)
      for Automatic Transmission
      Tester Connection Condition Specified Condition
      S8-1 (FPC) - G55-4 (FPC) Always Below 1 Ω
      S8-2 (DI) - G55-14 (DI) Always Below 1 Ω
      S8-3 (E) - Body ground Always Below 1 Ω
      for Manual Transmission
      Tester Connection Condition Specified Condition
      S8-1 (FPC) - G55-3 (FPC) Always Below 1 Ω
      S8-2 (DI) - G56-26 (DI) Always Below 1 Ω
      S8-3 (E) - Body ground Always Below 1 Ω
      Standard Resistance (Check for Short)
      for Automatic Transmission
      Tester Connection Condition Specified Condition
      S8-1 (FPC) or G55-4 (FPC) - Body ground Always 10 kΩ or higher
      S8-2 (DI) or G55-14 (DI) - Body ground Always 10 kΩ or higher
      for Manual Transmission
      Tester Connection Condition Specified Condition
      S8-1 (FPC) or G55-3 (FPC) - Body ground Always 10 kΩ or higher
      S8-2 (DI) or G56-26 (DI) - Body ground Always 10 kΩ or higher

    4. Reconnect the fuel pump ECU connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. REPLACE FUEL PUMP ECU


    1. Replace the fuel pump ECU Click here.


    NEXT

  8. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED


    1. Check the fuel pump operation.

      OK
      Malfunction has been repaired successfully.

    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here

    NG

    REPLACE ECM Click here