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).

INSPECTION PROCEDURE

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. Click here

   PERFORM ACTIVE TEST USING INTELLIGENT TESTER (FUEL PUMP)

   
   

   1. Connect the intelligent tester to the DLC3.

   2. Turn the ignition switch to ON and turn the tester on.

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

   4. Check whether operating sounds can be heard while operating the relay using the tester.

      OK
      Operating sounds can be heard from relay.

   
   
   • OKClick here
   • NGClick here
2. Click here

   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)
      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)
      Tester Connection Condition Specified Condition S9-2 (FP-) - Body ground Always 10 kΩ or higher 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.

   
   
   • OKClick here
   • NGClick here
3. Click here

   REPLACE FUEL PUMP ECU

   
   

   1. Replace the fuel pump ECU (Click here).

   
   
   • NEXTClick here
4. Click here

   CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

   
   

   1. Check the fuel pump operation.

      OK
      Malfunction has been repaired successfully.

   
   
   • OKClick here
   • NGClick here
5. Click here

   INSPECT CIRCUIT OPENING RELAY (C/OPN)

   
   

   1. Inspect the circuit opening relay (C/OPN) (Click here).

   
   
   • OKClick here
   • NGClick here
6. Click here

   INSPECT CIRCUIT OPENING RELAY (C/OPN) (POWER SOURCE VOLTAGE)

   
   

   1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition C/OPN relay terminal 2 - Body ground Ignition switch ON 11 to 14 V C/OPN relay terminal 5 - Body ground Ignition switch ON 11 to 14 V

      Table 1. Text in Illustration

      *1	Engine Room Relay Block
      *2	Circuit Opening Relay (C/OPN)

   3. Reinstall the circuit opening relay (C/OPN).

   
   
   • OKClick here
   • NGClick here
7. Click here

   CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - ECU, FUEL PUMP ECU)

   
   

   1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

   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)
      Tester Connection Condition Specified Condition C/OPN relay terminal 1 - G56-8(FC) Always Below 1 Ω C/OPN relay terminal 3 - S8-4 (+B) Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition C/OPN relay terminal 1 or G56-8 (FC) - Body ground Always 10 kΩ or higher C/OPN relay terminal 3 or S8-4 (+B) - Body ground Always 10 kΩ or higher

   5. Reinstall the circuit opening relay (C/OPN).

   6. Reconnect the fuel pump ECU connector.

   7. Reconnect the ECM connector.

   
   
   • OKClick here
   • NGClick here
8. Click here

   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.

   
   
   • OKClick here
   • NGClick here
9. Click here

   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).

      Table 2. Result

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

   
   
   • AClick here
   • BClick here
   • CClick here
10. Click here

    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)
       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)
       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.

    
    
    • OKClick here
    • NGClick here
11. Click here

    REPLACE FUEL PUMP ECU

    
    

    1. Replace the fuel pump ECU (Click here).

    
    
    • NEXTClick here
12. Click here

    CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    
    

    1. Check the fuel pump operation.

       OK
       Malfunction has been repaired successfully.

    
    
    • OKClick here
    • NGClick here
13. Click here

    CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - IGN FUSE, NO. 1 INTEGRATION RELAY)

    
    

    1. Remove the circuit opening relay (C/OPN) from the engine room relay block.

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

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

       Standard Resistance (Check for Open)
       Tester Connection Condition Specified Condition C/OPN relay terminal 2 - 1A-5 Always Below 1 Ω C/OPN relay terminal 5 - 1B-4 Always Below 1 Ω

       Standard Resistance (Check for Short)
       Tester Connection Condition Specified Condition C/OPN relay terminal 2 or 1A-5 - Body ground Always 10 kΩ or more C/OPN relay terminal 5 or 1B-4 - Body ground Always 10 kΩ or more

    4. Reinstall the circuit opening relay (C/OPN).

    5. Reinstall the No. 1 integration relay.

    
    
    • OKClick here
    • NGClick here
14. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

15. Click here

    REPLACE ECMClick here

16. Click here

    REPLACE CIRCUIT OPENING RELAY (C/OPN)

17. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

18. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

19. Click here

    REPLACE FUEL PUMPClick here

20. Click here

    REPLACE FUEL PUMPClick here

21. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

22. Click here

    REPLACE ECMClick here

23. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

24. Click here

    END

25. Click here

    GO TO ECM POWER SOURCE CIRCUITClick here