SFI SYSTEM(w/o Canister Pump Module) 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 control ECU assembly adjusts the fuel pump operation speed between 3 settings.

WIRING DIAGRAM

Click here

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 engine switch on (IG).

   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 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

   INSPECT FUEL PUMP CONTROL ECU ASSEMBLY (POWER SOURCE VOLTAGE) Click here

   OK

2. CHECK HARNESS AND CONNECTOR (ECM - FUEL PUMP CONTROL ECU ASSEMBLY - FUEL SUCTION TUBE WITH PUMP AND GAUGE ASSEMBLY)

   
   

   1. Disconnect the A12 ECM connector.

   2. Disconnect the U40 and U41 fuel pump control ECU assembly connectors.

   3. Disconnect the U8 fuel suction tube with pump and gauge assembly connector.

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

      Standard Resistance

      Tester Connection Condition Specified Condition A12-17 (FPC) - U41-1 (FPC) Always Below 1 Ω U40-1 (FP) - U8-4 (B2) Always Below 1 Ω U40-2 (FP-) - U8-5 (E2) Always Below 1 Ω A12-17 (FPC) or U41-1 (FPC) - Body ground and other terminals Always 10 kΩ or higher U40-1 (FP) or U8-4 (B2) - Body ground and other terminals Always 10 kΩ or higher U40-2 (FP-) or U8-5 (E2) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

3. REPLACE FUEL PUMP CONTROL ECU ASSEMBLY

   
   

   1. Replace the fuel pump control ECU assembly.

      Click here

      Result
      Proceed to NEXT

   
   

   NEXT

   GO TO STEP 9 Click here

4. INSPECT FUEL PUMP CONTROL ECU ASSEMBLY (POWER SOURCE VOLTAGE)

   

   *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 engine switch on (IG).

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition U41-4 (+B) - U41-3 (E) 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

5. CHECK HARNESS AND CONNECTOR (FUEL PUMP CONTROL ECU ASSEMBLY - FUEL SUCTION TUBE WITH PUMP AND GAUGE ASSEMBLY)

   
   

   1. Disconnect the U40 fuel pump control ECU assembly connector.

   2. Disconnect the U8 fuel suction tube with pump and gauge assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition U40-1 (FP) - U8-4 (B2) Always Below 1 Ω U40-2 (FP-) - U8-5 (E2) Always Below 1 Ω U40-1 (FP) or U8-4 (B2) - Body ground and other terminals Always 10 kΩ or higher U40-2 (FP-) or U8-5 (E2) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

6. INSPECT FUEL PUMP WITH FILTER ASSEMBLY (FOR LOW PRESSURE SIDE)

   
   

   1. Inspect the fuel pump with filter assembly (for low pressure side).

      Click here

      Tech Tips

      Perform "Inspection After Repair" after replacing the fuel pump with filter assembly (for low pressure side).

      Click here

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE FUEL PUMP WITH FILTER ASSEMBLY (FOR LOW PRESSURE SIDE) Click here

   OK

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

   
   

   1. Disconnect the A12 ECM connector.

   2. Disconnect the U41 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 A12-17 (FPC) - U41-1 (FPC) Always Below 1 Ω A12-14 (DI) - U41-2 (DI) Always Below 1 Ω A12-17 (FPC) or U41-1 (FPC) - Body ground and other terminals Always 10 kΩ or higher A12-14 (DI) or U41-2 (DI) - Body ground and other terminals 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.

      Click here

      OK
      Malfunction has been repaired successfully.

      Result
      Proceed to OK NG

   
   

   OK

   END

   NG

   REPLACE ECM Click here

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

    
    

    1. Disconnect the U41 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 U41-3 (E) - Body ground Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

11. INSPECT C/OPN RELAY

    
    

    1. Inspect the C/OPN relay.

       Click here

       Result
       Proceed to OK NG

    
    

    NG

    REPLACE C/OPN RELAY

    OK

12. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - FUEL PUMP CONTROL ECU ASSEMBLY)

    
    

    1. Remove the C/OPN relay from the No. 3 engine room relay block.

    2. Disconnect the U41 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 (C/OPN relay holder) - U41-4 (+B) Always Below 1 Ω 3 (C/OPN relay holder) or U41-4 (+B) - Body ground Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    NG

    REPLACE EFI MAIN NO. 2 RELAY

    OK

13. CHECK HARNESS AND CONNECTOR (EFI MAIN NO. 2 RELAY - C/OPN RELAY)

    
    

    1. Remove the EFI MAIN NO. 2 relay from the No. 3 engine room relay block.

    2. Remove the C/OPN relay from the No. 3 engine room relay block.

    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 holder) - 5 (C/OPN relay holder) Always Below 1 Ω 3 (EFI MAIN NO. 2 relay holder) - 1 (C/OPN relay holder) Always Below 1 Ω 3 (EFI MAIN NO. 2 relay holder) or 5 (C/OPN relay holder) - Body ground and other terminals Always 10 kΩ or higher 3 (EFI MAIN NO. 2 relay holder) or 1 (C/OPN relay holder) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

14. 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

15. CHECK HARNESS AND CONNECTOR (EFI MAIN NO. 2 RELAY - ECM)

    
    

    1. Remove the EFI MAIN NO. 2 relay from the No. 3 engine room relay block.

    2. Disconnect the A12 ECM connector.

    3. 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 holder) - A12-3 (MREL) Always Below 1 Ω 1 (EFI MAIN NO. 2 relay holder) or A12-3 (MREL) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

16. CHECK HARNESS AND CONNECTOR (EFI MAIN NO. 2 RELAY - BODY GROUND)

    
    

    1. Remove the EFI MAIN NO. 2 relay from the No. 3 engine room relay block.

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

       Standard Resistance
       Tester Connection Condition Specified Condition 2 (EFI MAIN NO. 2 relay holder) - Body ground Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - EFI MAIN NO. 2 RELAY)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR