2008 Lexus ES 350FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. PERFORM ACTIVE TEST BY TECHSTREAM (OPERATE VSV FOR ACIS) 
    1. Connect Techstream to the DLC3.
    2. Start the engine and turn Techstream on.
    3. Select the following menu items: Powertrain / Engine / Active Test / Activate the VSV for Intake Control. Operate the VSV for AICS.

      OK: 

      Operational noise can be heard. 

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

    NG: Go to next step. 

  2. CHECK INTAKE AIR CONTROL VALVE (OPERATION) 
    1. Disconnect the B41 VSV for ACIS connector.
    2. Apply battery voltage between the terminals of the air intake control valve connector.
    3. Check the air intake valve operation.
      Fig 1: Identifying Terminals Of B41 VSV For ACIS Connector
      G05835592Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK: 

      Operational noise can be heard. 

    NG: REPLACE INTAKE AIR SURGE TANK 

    OK: Go to next step. 

  3. CHECK HARNESS AND CONNECTOR (VSV FOR ACIS - ECM, VSV FOR ACIS - EFI RELAY) 
    1. Check the wire harness and connectors between the VSV for ACIS and ECM.
      1. Disconnect the B41 VSV for ACIS connector.
      2. Disconnect the B12 ECM connector.
      3. Measure the resistance according to the value(s) in the table below.

        Standard Resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        VSV for ACIS (B41-1) - ACIS (B12-107) Below 1 Ω

        Standard Resistance (Check for short) 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        VSV for ACIS (B41-1) or ACIS (B12-107) - Body ground 10 kΩ or higher
      4. Reconnect the VSV for ACIS connector.
      5. Reconnect the ECM connector.
    2. Check the EFI No. 3 fuse.
      1. Remove the EFI No. 3 fuse from the engine room R/B.
      2. Measure the EFI No. 3 fuse resistance.

        Standard Resistance: 

        Below 1 Ω 

      3. Reinstall the EFI No. 3 fuse.
    3. Check the wire harness between the VSV for ACIS connector and EFI relay.
      1. Remove the engine room junction block from the engine room R/B.
      2. Disconnect the B41 VSV for ACIS connector.
      3. Measure the resistance between the terminals.

        Standard Resistance (Check for open) 

        TESTER CONNECTION SPECIFIED CONDITION CHART

        Tester Connection Specified Condition
        VSV for ACIS (B41 -2) - 1E-6 Below 1 Ω
        Fig 2: Identifying Terminals Of B41 VSV For ACIS And B12 ECM Connectors
        G05835593Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      4. Reinstall the engine room junction block.
      5. Reconnect the VSV connector.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: REPLACE ECM (See  REMOVAL   ) 

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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