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Home >> Lexus >> 2008 >> LS 600hL >> Repair and Diagnosis (Single Page) >> Engine Performance >> Engine Control Systems >> Engine Control System - Circuit Tests, Component Removal, Inspection & Installation >> Fuel Pump Control Circuit >> Inspection Procedure
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Inspection Procedure

  1. CHECK FUEL PUMP OPERATION 
    1. Check the fuel pressure (see ON-VEHICLE INSPECTION ).

      HINT:

      If there is fuel pressure, you will hear the sound of fuel flowing.

    NG:  Go to step  5

    OK: Go to next step 

  2. INSPECT FUEL PUMP RELAY (F/PMP) 
    1. Inspect the F/PMP relay (see ON-VEHICLE INSPECTION  ).

    NG: REPLACE FUEL PUMP RELAY (F/PMP)  (See ON-VEHICLE INSPECTION  )

    OK: Go to next step 

  3. INSPECT FUEL PUMP RESISTOR 
    1. Inspect the fuel pump resistor resistance
      2. Fig 1: Inspecting Fuel Pump Resistor
      G04942988Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value (s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      1 - 2 20°C (68°F) 0.941 to 0.999 Ω

    NG: REPLACE FUEL PUMP RESISTOR  (See REMOVAL )

    OK: Go to next step 

  4. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) TO FUEL PUMP) 
    1. Check the harness and connector.
      1. Remove the C/OPN relay and F/PMP relay from the engine room No. 2 relay block.
      2. Disconnect the A16 fuel pump resistor connector.
        3. Fig 2: Identifying A16 Fuel Pump Connector Terminal
        G05771178Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Measure the resistance according to the value (s) in the table below.

        Standard resistance (Check for open) 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        C/OPN relay (3) - F/PMP relay (4) Always Below 1 Ω
        C/OPN relay (3) - A16-1 Always Below 1 Ω

        Standard resistance (Check for short) 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        C/OPN relay (3) or F/ PMP relay (4) - Body ground Always 10 kΩ or higher
        C/OPN relay (3) or A16-1 - Body ground Always 10 kΩ or higher
    2. Check the harness and connector.
      1. Remove the F/PMP relay from the engine room No. 2 relay block.
      2. Disconnect the A16 fuel pump resistor connector.
      3. Disconnect the S11 fuel pump connector.
      4. Measure the resistance according to the value (s) in the table below.

        Standard resistance (Check for open) 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        F/PMP relay (3) - S11-4 Always Below 1 Ω
        A16-2 - S11-4 Always Below 1 Ω

        Standard resistance (Check for short) 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        F/PMP relay (3) or S11-4 - Body ground Always 10 kΩ or higher
        A16-2 or S11-4 - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE ECM  (See REMOVAL  )

  5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (OPERATE CIRCUIT OPENING RELAY [C/OPN]) 
    1. Connect the intelligent tester or Techstream to the DLC3.
    2. Turn the power switch ON (IG) and turn the tester ON.
    3. Enter the following menus.
      1. Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP /SPD.
      2. Techstream - Select: Powertrain / Engine and ECT / Active Test / Activate the Fuel Pump Speed Control.
    4. Check whether operating sounds can be heard while operating the relay using the tester.

      OK: Operating sounds can be heard from relay. 

    NG:  Go to step  14

    OK: Go to next step 

  6. INSPECT FUSE (EFI MAIN) 
    1. Remove the EFI MAIN fuse from the engine room No. 2 relay block.
      2. Fig 3: Identifying Engine Room No. 2 Relay Block Connector Terminal
      G05771179Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value (s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      EFI MAIN fuse Always Below 1 Ω

    NG: CHECK FOR SHORT IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

    OK: Go to next step 

  7. INSPECT EFI RELAY (EFI MAIN) 
    1. Inspect the EFI MAIN relay (see ON-VEHICLE INSPECTION  ).

    NG: REPLACE EFI MAIN RELAY  (See ON-VEHICLE INSPECTION  )

    OK: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - EFI MAIN RELAY) 
    1. Remove the EFI MAIN relay and C/OPN relay from the engine room No. 2 relay block.
    2. Measure the resistance according to the value (s) in the table below.

      Standard resistance (Check for open) 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      EFI MAIN relay (3) - C/ OPN relay (5) Always Below 1 Ω

      Standard resistance (Check for short) 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      EFI MAIN relay (3) or C/ OPN relay (5) - Body ground Always 10 kΩ or higher
      Fig 4: Identifying Engine Room No. 2 Relay Block Connector Terminal
      G05771180Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  9. INSPECT FUEL PUMP RELAY (F/PMP) 
    1. Inspect the F/PMP relay (see ON-VEHICLE INSPECTION  ).

    NG: REPLACE FUEL PUMP RELAY (F/PMP)  (See ON-VEHICLE INSPECTION  )

    OK: Go to next step 

  10. INSPECT FUEL PUMP RESISTOR 
    1. Inspect the fuel pump resister (see INSPECTION ).

    NG: REPLACE FUEL PUMP RESISTOR  (See INSPECTION )

    OK: Go to next step 

  11. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) TO FUEL PUMP) 
    1. Check the harness and connector.
      1. Remove the C/OPN relay and F/PMP relay from the engine room No. 2 relay block.
      2. Disconnect the A16 fuel pump resistor connector.
        3. Fig 5: Identifying A16 Fuel Pump Resistor Connector Terminal And S11 Fuel Pump Connector Terminal
        G05771178Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      3. Measure the resistance according to the value (s) in the table below.

        Standard resistance (Check for open) 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        C/OPN relay (3) - F/PMP relay (4) Always Below 1 Ω
        C/OPN relay (3) - A16-1 Always Below 1 Ω

        Standard resistance (Check for short) 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        C/OPN relay (3) or F/ PMP relay (4) - Body ground Always 10 kΩ or higher
        C/OPN relay (3) or A16-1 - Body ground Always 10 kΩ or higher
    2. Check the harness and connector.
      1. Remove the F/PMP relay from the engine room No. 2 relay block
      2. Disconnect the A16 fuel pump resistor connector.
      3. Disconnect the S11 fuel pump connector.
      4. Measure the resistance according to the value (s) in the table below.

        Standard resistance (Check for open) 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        F/PMP relay (3) - S11-4 Always Below 1 Ω
        A16-2 - S11-4 Always Below 1 Ω

        Standard resistance (Check for short) 

        STANDARD RESISTANCE

        Tester Connection Condition Specified Condition
        F/PMP relay (3) or S11-4 - Body ground Always 10 kΩ or higher
        A16-2 or S11-4 - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  12. INSPECT FUEL PUMP 
    1. Inspect the fuel pump (see INSPECTION ).

    NG: REPLACE FUEL PUMP  (See REMOVAL )

    OK: Go to next step 

  13. CHECK HARNESS AND CONNECTOR (FUEL PUMP - BODY GROUND) 
    1. Disconnect the S11 fuel pump connector.
      2. Fig 6: Identifying S11 Fuel Pump Connector Terminal
      G05771182Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value (s) in the table below

      Standard resistance 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      S11-5 - Body ground Always Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI MAIN RELAY - BATTERY) 

  14. INSPECT CIRCUIT OPENING RELAY (C/OPN) 
    1. Inspect the C/OPN relay (see ON-VEHICLE INSPECTION  ).

    NG: REPLACE CIRCUIT OPENING RELAY  (See ON-VEHICLE INSPECTION  )

    OK: Go to next step 

  15. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - EFI-B FUSE) 
    1. Remove the C/OPN relay and EFI-B fuse from the engine room No. 2 relay block
      2. Fig 7: Identifying Engine Room No. 2 Relay Block Connector Terminal
      G05771183Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance according to the value (s) in the table below

      Standard resistance (Check for open) 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      C/OPN relay (1) - EFI-B fuse (2) Always Below 1 Ω

      Standard resistance (Check for short) 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      C/OPN relay (1) or EFI-B fuse (2) - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  16. CHECK CIRCUIT OPENING RELAY [C/OPN] (POWER SOURCE) 
    1. Remove the C/OPN relay from the engine room No. 2 relay block.
      2. Fig 8: Identifying Engine Room No. 2 Relay Block Connector Terminal
      G05771184Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value (s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE

      Tester Connection Condition Specified Condition
      C/OPN relay (1) - Body ground Power switch ON (IG) 11 to 14 V

    NG: GO TO ECM POWER SOURCE CIRCUIT 

    OK: Go to next step 

  17. CHECK HARNESS AND CONNECTOR (CIRCUIT OPENING RELAY (C/OPN) - ECM) 
    1. Remove the C/OPN relay from the engine room No. 2 relay block.
      2. Fig 9: Identifying Engine Room No. 2 Relay Block Connector Terminal And A14 ECM Connector Terminal
      G05771185Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the A14 ECM connector.
    3. Measure the resistance according to the value (s) in the table below.

      Standard resistance (Check for open) 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      C/OPN relay (2) - A14-5 (FC) Always Below 1 Ω

      Standard resistance (Check for short) 

      STANDARD RESISTANCE

      Tester Connection Condition Specified Condition
      C/OPN relay (2) or A14-5 (FC) - Body ground Always 10 kΩ or higher

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE ECM  (See REMOVAL  )

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