2006 Lexus SC 430FACTORY OEM SERVICE PROCEDURE

Inspection Procedure

  1. PERFORM ACTIVE TEST (ACIS VSV) 
    1. Disconnect the vacuum hose from the port F on the ACIS VSV.
    2. Connect the hand-held tester to the DLC3.
    3. Start the engine.
    4. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / INTAKE CTL VSV1. Operate the ACIS VSV.
    5. Check the VSV's air flows when switching the VSV.

      OK: 

      RESISTANCE SPECIFICATIONS

      Tester Condition Specified condition
      VSV is ON Air from port E flows out through port F
      Fig 1: Disconnecting Vacuum Hose From Port F On ACIS VSV
      G02955668Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: Go to step   4 . 
    2. OK: Go to next step. 
  2. CHECK VACUUM HOSE (INTAKE MANIFOLD - ACIS VSV - IACV) 
    1. Check the condition of the vacuum hoses between the intake manifold, ACIS VSV and IACV.
      1. The vacuum hoses are connected securely.
      2. There are no cracks or damage on the vacuum hoses.

        OK: 

        The vacuum hoses are connected securely and there are no cracks or damages on the vacuum hoses. 

    1. NG: REPAIR OR REPLACE VACUUM HOSE 
    2. OK: Go to next step. 
  3. INSPECT INTAKE AIR CONTROL VALVE ASSY (See  INSPECTION  ) 
    1. NG: REPLACE INTAKE AIR CONTROL VALVE ASSY 
    2. OK: REPLACE ECM (See  REPLACEMENT  ) 
  4. INSPECT ACIS VSV (OPERATION) 
    1. Check that air flows from port E to the air filter.

      OK: Air flows from port E to air filter 

      Fig 2: Checking If Air Flows From Port E To Air Filter
      G02955669Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Apply battery positive voltage across the terminals.
    3. Check that air flows from port E to port F.

      OK: Air flows from port E to port F 

      Fig 3: Applying Battery Positive Voltage Across Terminals & Checking If Air Flows From Port E To Port F
      G02955670Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPLACE ACIS VSV 
    2. OK: Go to next step. 
  5. CHECK WIRE HARNESS (ECM - ACIS VSV - EFI RELAY) 
    1. Check the wire harness between the ACIS VSV and ECM.
      1. Disconnect the V2 ACIS VSV connector.
      2. Disconnect the E4 ECM connector.
      3. Measure the resistance of the wire harness side connectors.

        Standard: 

        RESISTANCE SPECIFICATIONS

        Tester Connection Specified Condition
        V2-2 - E4-21 (ACIS) Below 1 ohms
        V2-2 or E4-21 (ACIS) - Body ground 10 k ohms or higher
        Fig 4: Identifying V2 ACIS VSV Connector Terminals
        G02955671Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the wire harness between the ACIS VSV and EFI relay.
      1. Disconnect the V2 ACIS VSV connector.
      2. Remove the EFI relay from the engine room No. 2 R/B.
      3. Measure the resistance between the wire harness side connectors.

        Standard: 

        RESISTANCE SPECIFICATIONS

        Tester Connection Specified Condition
        V2-1 - R/B EFI relay terminal 3 Below 1 ohms
        Fig 5: Removing EFI Relay From Engine Room No. 2 R/B
        G02955672Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    1. NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 
    2. OK: REPLACE ECM (See  REPLACEMENT  ) 
Factory Service Tools

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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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