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Home >> Lexus >> 2019 >> LX 570 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Diagnostic Codes (7 Of 7) & Circuit Tests >> SFI System >> Fuel Pump Control Circuit [09/2015 - 08/2018] >> Procedure
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Fuel Pump Control Circuit [09/2015 - 08/2018]: Procedure

  1. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP/SPEED) 
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump/Speed.
    5. Check whether operating sounds can be heard while operating the fuel pump using the Techstream.

      OK

      Operating sounds can be heard from fuel pump.

      RESULT

      Result Proceed to
      NG A
      OK B

    Result: 

    NG 

    See step  8

    Result: 

    OK 

    See step  2

  2. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE FUEL PUMP) 
    GTY329014Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Remove the fuel tank assembly (Refer to REMOVAL [09/2015 - ] ).
    2. Remove the fuel pump from the fuel tank assembly.
    3. Clean the fuel pump to completely remove any remaining fuel.
    4. Connect the fuel pump connector.
      WARNING:

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

    5. Connect the Techstream to the DLC3.
    6. Turn the engine switch on (IG).
    7. Turn the Techstream on.
    8. Enter the following menus: Powertrain / Engine / Active Test / Control the Fuel Pump Duty.
    9. 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 Techstream Operation Specified Condition
      1 - 2 FPC Duty: 25% 3.2 to 4.05 V
      FPC Duty: 80% 8.8 to 12.5 V
    10. Enter the following menus: Powertrain / Engine / 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 Techstream Operation Specified Condition
      1 - 2 ON (FPC Duty: 90%) 9.0 to 14.0 V

      HINT: 

      • Be sure to measure the voltage with all of the connectors connected.
      • Before performing this inspection, check that the battery voltage is between 11 and 14 V (not depleted).

    Result: 

    NG 

    See step  6

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM) 
    1. Disconnect the fuel pump 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
      N12-5 (FPC) - A38-50 (FPC) Always Below 1 Ω
      N12-5 (FPC) or A38-50 (FPC) - Body ground Always 10 kΩ or higher

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. REPLACE FUEL PUMP 
    1. Replace the fuel pump (Refer to REMOVAL [09/2015 - 08/2016] , or refer to REMOVAL [08/2016 - ] ).

      HINT: 

      Perform "Inspection After Repair" after replacing the fuel pump (Refer to INITIALIZATION [09/2015 - ] ).

    Result: 

    NEXT 

    See step  5

  5. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 
    1. Check the fuel pump operation.

      OK

      Malfunction has been repaired successfully.

    Result: 

    OK 

    END 

    Result: 

    NG 

    REPLACE ECM 

    (Refer to REMOVAL [09/2015 - ] )

  6. REPLACE FUEL PUMP ECU 
    1. Replace the fuel pump ECU (Refer to REMOVAL [09/2015 - ] ).

    Result: 

    NEXT 

    See step  7

  7. CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED 
    1. Check the fuel pump operation.

      OK

      Malfunction has been repaired successfully.

    Result: 

    OK 

    END 

    Result: 

    NG 

    REPLACE ECM 

    (Refer to REMOVAL [09/2015 - ] )

  8. INSPECT FUEL PUMP ECU (POWER SOURCE VOLTAGE) 
    GTY620150Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. Disconnect the fuel pump ECU 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
      N12-6 (+B) - Body Ground Engine switch on (IG) 11 to 14 V

    Result: 

    NG 

    See step  12

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (FUEL PUMP - FUEL PUMP ECU) 
    1. Disconnect the fuel pump connector.
    2. Disconnect the fuel pump ECU connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      N1-4 (B2) - N12-1 (FP) Always Below 1 Ω
      N1-5 (E2) - N12-2 (FP-) Always Below 1 Ω
      N1-4 (B2) or N12-1 (FP) - Body ground Always 10 kΩ or higher
      N1-5 (E2) or N12-2 (FP-) - Body ground Always 10 kΩ or higher

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. INSPECT FUEL PUMP 
    1. Inspect the fuel pump (Refer to INSPECTION [09/2015 - ] ).

      HINT: 

      Perform "Inspection After Repair" after replacing the fuel pump (Refer to INITIALIZATION [09/2015 - ] ).

    Result: 

    NG 

    REPLACE FUEL PUMP 

    (Refer to REMOVAL [09/2015 - 08/2016] , or refer to REMOVAL [08/2016 - ] )

    Result: 

    OK 

    See step  11

  11. CHECK HARNESS AND CONNECTOR (FUEL PUMP ECU - ECM, BODY GROUND) 
    1. Disconnect the fuel pump 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
      A38-50 (FPC) - N12-5 (FPC) Always Below 1 Ω
      N12-3 (E) - Body ground Always Below 1 Ω
      A38-50 (FPC) or N12-5 (FPC) - Body ground Always 10 kΩ or higher

    Result: 

    OK 

    REPLACE FUEL PUMP ECU 

    (Refer to REMOVAL [09/2015 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  12. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - FUEL PUMP ECU) 
    1. Disconnect the fuel pump ECU connector.
    2. Disconnect the integration relay connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      1P-6 - N12-6 (+B) Always Below 1 Ω
      1P-6 or N12-6 (+B) - Body ground Always 10 kΩ or higher

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  13

  13. INSPECT INTEGRATION RELAY (FUEL PMP) 
    1. Inspect the integration relay (FUEL PMP) (Refer to PROCEDURE - Step 2 ).

    Result: 

    OK 

    GO TO ECM POWER SOURCE CIRCUIT 

    (Refer to ECM Power Source Circuit [09/2015 - ] )

    Result: 

    NG 

    REPLACE INTEGRATION RELAY 

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