SFI SYSTEM(w/ EGR 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 power switch on (IG).

   3. Turn the GTS on.

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

      
      Powertrain > Engine and ECT > Active Test

      Tester Display
      Control the Fuel Pump / Speed

   5. Check whether the fuel pump operating sounds occurs when performing the Active Test on the GTS.

      Result
      Result Proceed to Fuel pump operating sound does not occur A Fuel pump operating sound occurs B

   
   

   B

   PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP DUTY) Click here

   A

2. 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 power 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) - Q14-4 (E) Power 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

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

   
   

   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 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 Always 10 kΩ or higher b1-5 (E) or Q14-5 (FP-) - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

4. 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

   GO TO STEP 14 Click here

   NG

   REPLACE FUEL PUMP Click here

5. 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

6. 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

7. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK - FUEL PUMP CONTROL ECU ASSEMBLY, AUXILIARY BATTERY)

   

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

   
   

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

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

   3. Disconnect the fuel pump control ECU assembly connector.

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

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

   5. 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

   
   

   OK

   GO TO ECM POWER SOURCE CIRCUIT Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

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

   
   

   1. Remove the fuel suction tube assembly.

      Click here

   2. Clean the fuel suction tube assembly to completely remove any remaining fuel.

   3. Remove the fuel pump.

      Click here

   4. Connect the fuel pump and fuel suction tube assembly connectors.

      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 power switch on (IG).

   7. Turn the GTS on.

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

      
      Powertrain > Engine and ECT > Active Test

      Tester Display
      Control the Fuel Pump Duty

   9. 

      *a	Component with harness connected (Fuel Pump)

      Operate the fuel pump using the Active Test 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 and ECT / Active Test / Control the Fuel Pump / Speed.

       
       Powertrain > Engine and ECT > Active Test

       Tester Display
       Control the Fuel Pump / Speed

   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

   INSPECT FUEL PUMP Click here

   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 Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

10. REPLACE FUEL PUMP

    
    

    1. Replace the fuel pump.

       Click here

       Tech Tips

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

       Click here

       Result
       Proceed to NEXT

    
    

    NEXT

    GO TO STEP 16 Click here

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 - FUEL PUMP CONTROL ECU ASSEMBLY)

    
    

    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 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 Always 10 kΩ or higher b1-5 (E) or Q14-5 (FP-) - 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 - 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

14. 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 Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

15. REPLACE FUEL PUMP CONTROL ECU ASSEMBLY

    
    

    1. Replace the fuel pump control ECU assembly.

       Click here

       Result
       Proceed to NEXT

    
    

    NEXT

16. 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