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Home >> Lexus >> 2008 >> ES 350 >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System - System & Component Testing, Removal, Inspection & Installation >> Fuel Pump Control Circuit >> Inspection Procedure
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Inspection Procedure

  1. PERFORM ACTIVE TEST BY TECHSTREAM (OPERATE C/OPN RELAY) 
    1. Connect Techstream to the DLC3.
    2. Turn the engine switch on (IG) and turn the tester on.
    3. Select the following menu items: Powertrain / Engine / Active Test / Control the Fuel Pump / Speed.
    4. Check whether the fuel pump operation sound occurs when performing the Active Test on the tester.

      OK: 

      Fuel pump operating sound occurs. 

    NG: Go to step 2 

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE (See  PROBLEM SYMPTOMS TABLE  ) 

  2. CHECK ECM POWER SOURCE CIRCUIT 

    NG: REPAIR OR REPLACE ECM POWER SOURCE CIRCUIT 

    OK: Go to next step. 

  3. INSPECT ENGINE ROOM JUNCTION BLOCK (C/OPN RELAY) 
    1. Remove the integration relay from the engine room relay block.
    2. Inspect the C/OPN relay.
      1. Measure the C/OPN relay resistance.

        Standard Resistance 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        1E-7 - 1E-13 10 kΩ or higher
        Below 1 Ω
        (Apply battery voltage between terminals 1D-12 and 1E-8)
        Fig 1: Identifying Engine Room Junction Block
        G04973814Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reinstall the integration relay.

    NG: REPLACE ENGINE ROOM JUNCTION BLOCK 

    OK: Go to next step. 

  4. INSPECT ECM (FC VOLTAGE) 
    1. Disconnect the A10 and B12 ECM connectors.
    2. Measure the voltage between the terminals of the A10 and B12 ECM connectors.

      Standard Voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART

      Tester Connection Specified Condition
      A10-7 (FC) - B12-81 (E1) 9 to 14 V
      Fig 2: Identifying Terminals Of A10 And A12 ECM Connectors
      G05247866Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reconnect the ECM connectors. NG

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BATTERY) 

    OK: Go to next step. 

  5. INSPECT FUEL PUMP 

    NG: REPLACE FUEL PUMP  (See REMOVAL )

    OK: Go to next step. 

  6. CHECK HARNESS AND CONNECTOR (C/OPN RELAY - FUEL PUMP - BODY GROUND) 
    1. Check the harness and the connectors between the engine room relay block and the fuel pump.
      1. Disconnect the integration relay connector.
      2. Disconnect the L13 fuel pump connector.
      3. Measure the resistance.

        Standard Resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        1E-13 - L13-4 (Fuel pump) Below 1 Ω

        Standard Resistance (Check for short) 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        1E-13 or L13-4 (Fuel pump) - Body ground 10 kΩ or higher
    2. Check the harness and the connectors between the fuel pump and body ground.
      1. Disconnect the L13 fuel pump connector.
      2. Measure the resistance.

        Standard Resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        L13 - 5 (Fuel pump) - Body ground Below 1 Ω
        Fig 3: Identifying Terminals Of L13 Fuel Pump Connector
        G05247867Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Reconnect the integration relay connector.
    4. Reconnect the fuel pump connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE ECM (See  REMOVAL   )