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Home >> Lexus >> 2021 >> LC 500 2D Convertible >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - Circuit Tests & Symptom Tests (Convertible) (2 Of 2) >> SFI System >> Air Intake Control Circuit [07/2020 - ] >> Procedure
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Air Intake Control Circuit [07/2020 - ]: Procedure

  1. PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE VSV FOR AICV) 
    GTY650250Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *1 Air
    *2 Port E
    *3 Port F
    *4 Air Filter
    *a Vacuum Switching Valve is On
    *b Vacuum Switching Valve is Off
    1. Connect the Techstream to the DLC3.
    2. Turn the engine switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine / Active Test / Activate the VSV for ACIS

      Powertrain > Engine > Active Test 

      Tester Display
      Activate the VSV for AICS
    5. Check for operation of the VSV when the VSV is operated using the Techstream.

      Standard

      Techstream Connection Specified Condition
      ON Air from port E flows out through port F
      OFF Air from port E flows out through the air filter

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [07/2020 - ] 

    Result: 

    NG 

    See step  2

  2. INSPECT VACUUM SWITCHING VALVE (FOR AICV) 
    1. Inspect the vacuum switching valve assembly (for AICV).

      Refer to PROCEDURE - Step 3

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE VACUUM SWITCHING VALVE (FOR AICV) 

    Result: 

    OK 

    See step  3

  3. CHECK TERMINAL VOLTAGE (POWER SOURCE OF VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV)) 
    GTY832025Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    *a Front view of wire harness connector
    (to Vacuum Switching Valve Assembly (for AICV))
    1. Disconnect the vacuum switching valve assembly (for AICV) connector.
    2. Turn the engine switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A62-2 - Body ground Engine switch on (IG) 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  6

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV) - ECM) 
    1. Disconnect the vacuum switching valve assembly (for AICV) connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A62-1 - A58-5 (AICV) Always Below 1 Ω
      A62-1 or A58-5 (AICV) - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  5

  5. INSPECT VACUUM SURGE TANK 
    1. Inspect the vacuum surge tank.

      Refer to PROCEDURE - Step 2

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECM. Refer to  REMOVAL [07/2020 - 05/2023]  , or refer to  REMOVAL [05/2023 - ] 

    Result: 

    NG 

    REPLACE VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV) 

  6. CHECK HARNESS AND CONNECTOR (EFI-MAIN RELAY NO. 1 - VACUUM SWITCHING VALVE ASSEMBLY (FOR AICV)) 
    1. Remove the EFI-MAIN NO. 1 relay and A/F HTR relay from No. 1 engine room relay block and junction block assembly.

      HINT: 

      Remove the A/F HTR relay connected between the checked terminals as the coil inside the relay influences the measurement value.

    2. Disconnect the vacuum switching valve assembly (for AICV) connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      3(EFI-MAIN NO. 1 relay holder) - A62-2 Always Below 1 Ω
      3(EFI-MAIN NO. 1 relay holder) or A62-2 - Body ground and other terminals Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    GO TO ECM POWER SOURCE CIRCUIT. Refer to  ECM Power Source Circuit [07/2020 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR