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Home >> Lexus >> 2007 >> GS 450h >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Component And System Testing, On-Vehicle Inspection, Removal, Inspection & Installation >> Fuel Pump Control Circuit >> Inspection Procedure
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Inspection Procedure

  1. PERFORM ACTIVE TEST BY INTELLIGENT TESTER (FUEL PUMP/SPD) 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the power switch ON (IG) and turn the tester ON.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / FUEL PUMP/SPD.
    4. Check whether the fuel pump operating sound occurs when perform the ACTIVE TEST on the tester.

      OK: 

      Fuel pump operating sound occurs. 

    OK:  GO TO step  10

    NG: GO TO Next Step 

  2. INSPECT INTEGRATION RELAY 
    1. Remove the integration relay (Unit A) from the engine room No. 1 junction block.
    2. Inspect the F/PMP fuse.
      1. Remove the F/PMP fuse from the integration relay.
      2. Measure the resistance of the F/PMP fuse.

        Standard resistance: 

        Below 1 Ω 

      3. Reinstall the F/PMP fuse.
    3. Inspect the EFI NO.2 and C/OPN relay.
      1. Measure the resistance of the EFI NO.2 and C/OPN relays.

        Standard resistance 

        EFI NO.2 relay 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        1R-1 - 1S-7 10 kΩ or higher
        Below 1 Ω (Apply battery voltage between terminals 1T-8 and 1S-3)

        C/OPN relay 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        1R-1 - 1S-8 10 kΩ or higher
        Below 1 Ω (Apply battery voltage between terminals 1T-8 and 1S-3,1R-1 and 1S-7)
    4. Reinstall the integration relay.
      Fig 1: Identifying F/PMP Fuse
      G05302508Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE INTEGRATION RELAY 

    OK: GO TO Next Step 

  3. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, INTEGRATION RELAY - FUEL PUMP RESISTOR) 
    1. Remove the integration relay (Unit A) from the engine room No. 1 junction block.
    2. Disconnect the A53 ECM connector.
    3. Disconnect the A45 fuel pump resistor connector.
    4. Measure the resistance.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      Engine room No. 1 junction block (1S-7) - FC (A53-7) Below 1 Ω
      Engine room No. 1 junction block (1S-8) - A45-1 Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      Engine room No. 1 junction block (1S-7) or FC (A53-7) - Body ground 10 kΩ or higher
      Engine room No. 1 junction block (1S-8) or A45-1 - Body ground 10 kΩ or higher
    5. Reinstall the integration relay.
    6. Reconnect the ECM connector.
    7. Reconnect the fuel pump resistor.
      Fig 2: Identifying Fuel Pump Resistor Connector Terminals
      G05302509Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: GO TO Next Step 

  4. INSPECT ECM POWER SOURCE CIRCUIT 

    NG: REPAIR OR REPLACE POWER SOURCE CIRCUIT COMPONENTS 

    OK: GO TO Next Step 

  5. INSPECT F/PMP RELAY 
    1. Remove the F/PMP relay from the engine room No. 1 relay block.
    2. Measure the resistance of the F/PMP relay.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      3 - 4 10 kΩ or higher
      3 - 4 Below 1 Ω (when battery voltage applied to terminals 1 and 2)
      Fig 3: Inspecting F/PMP Relay
      G05302510Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE F/PMP RELAY 

    OK: GO TO Next Step 

  6. INSPECT FUEL PUMP RESISTOR 
    1. Remove the fuel pump resistor.
    2. Measure the resistance of the fuel pump resistor.

      Standard resistance: 

      0.30 to 0.34 Ω at 20°C (68°F) 

      Fig 4: Measuring Resistance Of Fuel Pump Resistor Terminals
      G04962581Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE FUEL PUMP RESISTOR 

    OK: GO TO Next Step 

  7. INSPECT FUEL PUMP FOR LOW PRESSURE SIDE 
    1. Remove the rear seat cushion.
    2. Disconnect the V11 fuel pump connector.
    3. Inspect fuel pump resistance.
      1. Measure the resistance between terminals 4 and 5.

        Standard resistance: 

        0.2 to 3.0 Ω at 20°C (68°F) 

    4. Inspect fuel pump operation.
      1. Apply battery voltage to both the terminals. Check that the pump operates.
        NOTE:
        • These tests must be done quickly (within 10 seconds) to prevent the coil from burning out.
        • Keep the fuel pump as far away from the battery as possible.
        • Always turn the voltage on and off on the battery side, not the fuel pump side.
          Fig 5: Identifying Fuel Pump Connector Terminals
          G05302512Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE FUEL PUMP FOR LOW PRESSURE SIDE 

    OK: GO TO Next Step 

  8. CHECK HARNESS AND CONNECTOR (F/PMP RELAY - ECM, F/PMP RELAY - FUEL PUMP RESISTOR) 
    1. Remove the F/PMP relay from the engine room No. 1 relay block.
    2. Disconnect the A53 ECM connector.
    3. Disconnect the A45 fuel pump resistor connector.
    4. Measure the resistance of the wire harness side connectors.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      F/PMP relay (2) - FPR (A53-6) Below 1 Ω
      F/PMP relay (1) - A45-1 Below 1 Ω
      F/PMP relay (3) - A45-1 Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      F/PMP relay (2) or FPR (A53-6) - Body ground 10 kΩ or higher
      F/PMP relay (1) or A45-1 - Body ground 10 kΩ or higher
      F/PMP relay (3) or A45-1 - Body ground 10 kΩ or higher
      Fig 6: Identifying F/PMP Relay
      G05302513Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: GO TO Next Step 

  9. CHECK HARNESS AND CONNECTOR (F/PMP RELAY - FUEL PUMP, FUEL PUMP RESISTOR - FUEL PUMP, FUEL PUMP - BODY GROUND) 
    1. Remove the F/PMP relay from the engine room No. 1 relay block.
    2. Disconnect the V11 fuel pump connector.
    3. Disconnect the A45 fuel pump resistor connector.
    4. Measure the resistance.

      Standard resistance (Check for open) 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      F/PMP relay (4) - V11-4 Below 1 Ω
      A45-2 - V11-4 Below 1 Ω
      V11-5 - Body ground Below 1 Ω

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      F/PMP relay (4) or V11-4 - Body ground 10 kΩ or higher
      A45-2 or V11-4 - Body ground 10 kΩ or higher
    5. Reconnect the fuel pump resistor connector.
    6. Reconnect the fuel pump connector.
    7. Reinstall the F/PMP relay.
      Fig 7: Identifying Fuel Pump Resistor Connector Terminals
      G05302514Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE ECM 

  10. READ VALUE OF INTELLIGENT TESTER (ENGINE SPD) 
    1. Connect the intelligent tester to the DLC3.
    2. Turn the power switch ON (IG) and turn the tester ON.
    3. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / ENGINE SPD.
    4. Read the values displayed on the tester while cranking.

      OK: 

      Values are displayed continuously. 

    NG: REPAIR OR REPLACE CRANKSHAFT POSITION SENSOR 

    OK: REPLACE ECM 

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