SFI SYSTEM Fuel Pump Control Circuit

DESCRIPTION

The fuel pump circuit consists of the ECM, fuel pump and fuel pump control 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 control ECU. Based on the signal sent from the ECM, the fuel pump control ECU adjust 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 and ECT / Active Test / Control the Fuel Pump / Speed.

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

   
   

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

      Click here

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

   3. Remove the fuel pump.

      Click here

   4. Connect the fuel pump and fuel suction with pump and gauge 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 ignition switch to ON.

   7. Turn the GTS on.

   8. Enter the following menus: Powertrain / Engine and ECT / Active Test / 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% 3.4 to 4.1 V Fuel pump control duty: 80% 10.0 to 12.5 V

   10. Enter the following menus: Powertrain / Engine and ECT / Active Test / 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%) 10.2 to 14.0 V

       Tech Tips

       
       

       • Be sure to measure the voltage with 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

   GO TO STEP 7 Click here

   OK

3. INSPECT FUEL PUMP

   
   

   1. Inspect the fuel pump.

      Click here

      Result
      Proceed to OK NG

   
   

   OK

   END

   NG

4. 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

5. 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

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

   

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

   
   

   1. Disconnect the fuel pump control ECU 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 Switch Condition Specified Condition A113-6 (+B) - Body ground Ignition switch ON 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

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

   OK

7. 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

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

   
   

   1. Disconnect the A113 fuel pump control ECU connector.

   2. Disconnect the K17 fuel pump connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition K17-4 (B) - A113-1 (FP) Always Below 1 Ω K17-5 (E) - A113-2 (FP-) Always Below 1 Ω K17-4 (B) or A113-1 (FP) - Body ground and other terminals Always 10 kΩ or higher K17-5 (E) or A113-2 (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 - ECM)

   
   

   1. Disconnect the fuel pump control ECU 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 A113-5 (FPC) - A58-41 (FPC) Always Below 1 Ω A113-5 (FPC) or A58-41 (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. PERFORM ACTIVE TEST USING GTS (CONTROL THE FUEL PUMP / SPEED (INSPECT ECM))

    
    
    1. 

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

       Disconnect the fuel pump control ECU connector.

    2. Connect the GTS to the DLC3.

    3. Turn the ignition switch to ON.

    4. Turn the GTS on.

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

    6. Operate the fuel pump control ECU assembly using the Active Test function and measure the resistance according to the value(s) in the table below.

       Standard Resistance
       Tester Connection GTS Operation Specified Condition A113-5 (FPC) - Body ground Before Active Test → During Active Test Before Active Test: Resistance is stable → During Active Test: Resistance fluctuates*

       Tech Tips

       *: Using the Active Test, duty control of the transistors in the ECM will be performed. Due to the duty control, resistance of the FPC terminal will be unstable during the Active Test. If the resistance is stable before the Active Test and fluctuates while performing the Active Test, it can be determined that the transistor is operating. If the transistor does not operate during the Active Test, the ECM may be malfunctioning.

       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 - BODY GROUND)

    
    

    1. Disconnect the fuel pump control ECU connector.

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

       Standard Resistance
       Tester Connection Condition Specified Condition A113-3 (E) - Body ground Always Below 1 Ω

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

12. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - FUEL PUMP CONTROL ECU)

    
    

    1. Remove the No. 1 integration relay connector.

    2. Disconnect the A113 fuel pump control ECU connector.

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

       Standard Resistance
       Tester Connection Condition Specified Condition 1E-4 - A113-6 (+B) Always Below 1 Ω 1E-4 or A113-6 (+B) - Body ground and other terminals Always 10 kΩ or higher

       Result
       Proceed to OK NG

    
    

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

13. INSPECT NO. 1 INTEGRATION RELAY

    
    

    1. Inspect the No. 1 integration relay.

       Click here

       Result
       Proceed to OK NG

    
    

    OK

    GO TO ECM POWER SOURCE CIRCUIT Click here

    NG

    REPLACE NO. 1 INTEGRATION RELAY