SFI SYSTEM(w/ GPF) Fuel Pump Control Circuit

DESCRIPTION

• The fuel pump circuit (for low pressure side) 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 adjust the fuel pump operation speed.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. PERFORM ACTIVE TEST USING GTS (ACTIVATE THE CIRCUIT RELAY)

   
   

   1. Connect the GTS to the DLC3.

   2. Turn the engine switch on (IG).

   3. Turn the GTS on.

   4. Enter the following menus: Powertrain / Engine / Active Test / Activate the Circuit Relay.

      
      Powertrain > Engine > Active Test

      Tester Display
      Activate the Circuit Relay

   5. 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 (for low pressure side).

      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 RATIO, ACTIVATE THE CIRCUIT RELAY)

   
   

   1. Remove the fuel suction with pump and gauge tube assembly.

   2. Clean the fuel suction with pump and gauge tube assembly to completely remove any remaining fuel.

   3. Remove the fuel pump (for low pressure side).

   4. Connect the fuel pump and fuel suction with pump and gauge tube assembly connector.

      Note

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

   5. Connect the GTS to the DLC3.

   6. Turn the engine switch on (IG).

   7. Turn the GTS on.

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

      
      Powertrain > Engine > Active Test

      Tester Display
      Control the Fuel Pump Duty Ratio

   9. 

      *a	Component with harness connected (Fuel Pump (for low pressure side))

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

      Standard Voltage
      Tester Connection GTS Operation Specified Condition 1 - 2 Fuel pump control duty: 25% 3.2 to 4.05 V Fuel pump control duty: 80% 8.8 to 12.5 V

   10. Enter the following menus: Powertrain / Engine / Active Test / Activate the Circuit Relay.

       
       Powertrain > Engine > Active Test

       Tester Display
       Control the Fuel Pump Duty Ratio

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

       Standard Voltage
       Tester Connection GTS Operation Specified Condition 1 - 2 ON (Fuel pump control duty: 90%) 9.0 to 14.0 V

       Tech Tips

       
       

       • Be sure to measure the voltage with all the 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

   GO TO STEP 7 Click here

   OK

3. INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE)

   
   

   1. Inspect fuel pump (for low pressure side).

      Click here

      Tech Tips

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

      Click here

      Result
      Proceed to OK NG

   
   

   OK

   END

   NG

4. REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE)

   
   

   1. Replace the fuel pump (for low pressure side).

      Click here

      Tech Tips

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

      Click here

      Result
      Proceed to NEXT

   
   

   NEXT

5. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED

   
   

   1. Check the fuel pump (for low pressure side) 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

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

   
   
   1. 

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

      Disconnect the fuel pump control ECU Assembly connector.

   2. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition Q14-1 (+B) - Body ground Engine switch on (IG) 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

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

   OK

7. INSPECT FUEL PUMP (FOR LOW PRESSURE SIDE)

   
   

   1. Inspect fuel pump (for low pressure side).

      Click here

      Tech Tips

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

      Click here

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE FUEL PUMP (FOR LOW PRESSURE SIDE) Click here

   OK

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

   
   

   1. Disconnect the fuel pump control ECU assembly connector.

   2. Disconnect the fuel suction plate sub-assembly (fuel pump) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition b1-4 (B) - Q14-6 (FP) Always Below 1 Ω b1-5 (E) - Q14-5 (FP-) Always Below 1 Ω b1-4 (B) or Q14-6 (FP) - Body ground and other terminals Always 10 kΩ or higher b1-5 (E) or Q14-5 (FP-) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

9. 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 Q14-2 (FPC) - A35-21 (FPC) Always Below 1 Ω Q14-2 (FPC) or A35-21 (FPC) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

10. CHECK ECM (FPC TERMINAL)

    
    
    1. 

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

       Disconnect the fuel pump control ECU assembly connector.

    2. Connect the GTS to the DLC3.

    3. Turn the engine switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Powertrain / Engine / Active Test / Activate the Circuit Relay.

       
       Powertrain > Engine > Active Test

       Tester Display
       Activate the Circuit Relay

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

       Standard Resistance
       Tester Connection Condition Specified Condition Q14-2 (FPC) - Body ground Active Test OFF → ON Active Test OFF: Resistance stabilized → ON: Resistance changes*

       Tech Tips

       *: The transistor inside the ECM performs duty control according to the Active Test being operated. The resistance of the FPC terminal changes while the Active Test is on due to duty control. If the resistance is stable while the Active Test is off and changes while the Active Test is on, the transistor is working correctly. If the transistor does not operate when the Active Test is on, there may be a malfunction in the ECM.

       Result
       Proceed to OK NG

    
    

    OK

    REPLACE FUEL PUMP CONTROL ECU ASSEMBLY

    NG

    REPLACE ECM Click here

11. 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 Q14-4 (E) - Body ground Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

12. INSPECT EFI-MAIN NO. 2 RELAY

    
    

    1. Inspect the EFI-MAIN NO. 2 relay.

       Click here

       Result
       Proceed to OK NG

    
    

    NG

    REPLACE EFI-MAIN NO. 2 RELAY

    OK

13. CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE OF EFI-MAIN NO. 2 RELAY)

    
    
    1. 

       *1	No. 1 Engine Room Relay Block and Junction Block Assembly
       *2	EFI-MAIN NO. 2 Relay

       Remove the EFI-MAIN NO. 2 relay from the No. 1 engine room relay block and junction block assembly.

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

       Standard Voltage
       Tester Connection Condition Specified Condition 5 (EFI-MAIN NO. 2 relay) - Body ground Always 11 to 14 V

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

14. CHECK HARNESS AND CONNECTOR (EFI-MAIN NO. 2 RELAY - EFI-MAIN NO. 1, FUEL PUMP CONTROL ECU ASSEMBLY, BODY GROUND)

    
    

    1. Remove the EFI-MAIN NO. 1 relay and EFI-MAIN NO. 2 relay from the No. 1 engine room relay block and junction block assembly.

    2. Disconnect the fuel pump control ECU assembly connector.

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

       Standard Resistance

       Tester Connection Condition Specified Condition 3 (EFI-MAIN NO. 2 relay) - Q14-1 (+B) Always Below 1 Ω 3 (EFI-MAIN NO. 1 relay) - 1 (EFI-MAIN NO. 2 relay) Always Below 1 Ω 2 (EFI-MAIN NO. 2 relay) - Body ground Always Below 1 Ω 3 (EFI-MAIN NO. 2 relay) or Q14-1 (+B) - Body ground and other terminals Always 10 kΩ or higher 3 (EFI-MAIN NO. 1 relay) or 1 (EFI-MAIN NO. 2 relay) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR