SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

The fuel pump circuit consists of the ECM, fuel pump and fuel pump control ECU assembly (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 control ECU assembly. Based on the signal sent from the ECM, the fuel pump ECU adjusts the fuel pump operation speed.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP / SPEED)

   
   

   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 / Active Test / Control the Fuel Pump / Speed.

      
      Powertrain > Engine > Active Test

      Tester Display
      Control the Fuel Pump / Speed

   5. Check whether fuel pump operating sounds can be heard while operating the fuel pump using the GTS.

      OK
      Operating sounds can be heard from the fuel pump.

      Result
      Proceed to OK NG

   
   

   NG

   CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL PUMP CONTROL ECU ASSEMBLY) Click here

   OK

2. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP DUTY)

   

   *a	Component with harness connected (Fuel Pump)

   
   

   1. Remove the fuel pump.

      Click here

   2. Clean the fuel pump to completely remove any remaining fuel.

   3. Connect the fuel pump connector.

      CAUTION:

      Confirm that no fuel remains inside or on the outside of the fuel pump.

   4. Connect the GTS to the DLC3.

   5. Turn the ignition switch to ON.

   6. Turn the GTS on.

   7. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump Duty.

      
      Powertrain > Engine > Active Test

      Tester Display
      Control the Fuel Pump Duty

   8. Operate the fuel pump using the Active Test and measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection GTS Operation Specified Condition 4 - 5 Fuel pump control duty: 25% 3.4 to 4.1 V Fuel pump control duty: 80% 10.0 to 12.5 V

   9. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump / Speed.

   10. Operate the fuel pump using the Active Test and measure the voltage according to the value(s) in the table below.

       Standard Voltage
       Tester Connection GTS Operation Specified Condition 4 - 5 ON (Fuel pump control duty: 90%) 10.2 to 14.0 V

       Tech Tips

       
       

       • Be sure to measure the voltage with the all connectors connected.

       • Before performing this inspection, check that the battery voltage is between 11 and 14 V (not depleted).

       Result
       Proceed to OK NG

   
   

   NG

   INSPECT FUEL PUMP Click here

   OK

3. 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

   END

   NG

4. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

   
   

   1. Check the fuel pump operation.

      OK
      Malfunction has been repaired successfully.

      Result
      Proceed to OK NG

   
   

   OK

   END

   NG

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

5. 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

   
   

   NG

   REPLACE FUEL PUMP Click here

   OK

6. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - FUEL PUMP)

   
   

   1. Disconnect the fuel pump control ECU assembly 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 M28-6 (FP) - M9-4 Always Below 1 Ω M28-5 (FP-) - M9-5 Always Below 1 Ω M28-6 (FP) or M9-4 - Body ground Always 10 kΩ or higher M28-5 (FP-) or M9-5 - 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 CONTROL ECU ASSEMBLY - ECM)

   
   

   1. Disconnect the fuel pump control ECU assembly 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 M28-2 (FPC) - A43-18 (FPC) Always Below 1 Ω M28-2 (FPC) or A43-18 (FPC) - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

8. REPLACE FUEL PUMP CONTROL ECU ASSEMBLY

   
   

   1. Replace the fuel pump control ECU assembly.

      Click here

      Result
      Proceed to NEXT

   
   

   NEXT

9. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

   
   

   1. Check the fuel pump operation.

      OK
      Malfunction has been repaired successfully.

      Result
      Proceed to OK NG

   
   

   OK

   END

   NG

   REPLACE ECM Click here

10. CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL PUMP CONTROL ECU ASSEMBLY)

    

    *a	Front view of wire harness connector (to Fuel Pump Control ECU Assembly)

    
    

    1. Disconnect the fuel pump control ECU assembly connector.

    2. Turn the ignition switch to ON.

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

       Standard Voltage
       Tester Connection Condition Specified Condition M28-1 (+B) - M28-4 (E) Ignition switch ON 11 to 14 V

       Result
       Proceed to OK NG

    
    

    NG

    CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - BODY GROUND) Click here

    OK

11. 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

    
    

    NG

    REPLACE FUEL PUMP Click here

    OK

12. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - FUEL PUMP)

    
    

    1. Disconnect the fuel pump control ECU assembly 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 M28-6 (FP) - M9-4 Always Below 1 Ω M28-5 (FP-) - M9-5 Always Below 1 Ω M28-6 (FP) or M9-4 - Body ground Always 10 kΩ or higher M28-5 (FP-) or M9-5 - Body ground Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

13. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - ECM)

    
    

    1. Disconnect the fuel pump control ECU assembly 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 M28-2 (FPC) - A43-18 (FPC) Always Below 1 Ω M28-2 (FPC) or A43-18 (FPC) - Body ground Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

14. REPLACE FUEL PUMP CONTROL ECU ASSEMBLY

    
    

    1. Replace the fuel pump control ECU assembly.

       Click here

       Result
       Proceed to NEXT

    
    

    NEXT

15. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

    
    

    1. Check the fuel pump operation.

       OK
       Malfunction has been repaired successfully.

       Result
       Proceed to OK NG

    
    

    OK

    END

    NG

    REPLACE ECM Click here

16. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - BODY GROUND)

    
    

    1. Disconnect the fuel pump control ECU assembly connector.

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

       Standard Resistance
       Tester Connection Condition Specified Condition M28-4 (E) - Body ground Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

17. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - SEMICONDUCTOR PWR INTEGRATION ECU)

    
    

    1. Disconnect the fuel pump control ECU assembly connector.

    2. Disconnect the semiconductor pwr integration ECU connector.

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

       Standard Resistance
       Tester Connection Condition Specified Condition M28-1 (+B) - 1G-8 Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

18. INSPECT SEMICONDUCTOR PWR INTEGRATION ECU

    
    

    1. Inspect the semiconductor pwr integration ECU (EFI MAIN relay).

       Click here

       Result
       Proceed to OK NG

    
    

    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here

    NG

    REPLACE SEMICONDUCTOR PWR INTEGRATION ECU Click here