LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2009 >> IS 250 AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (DTCS P0420 - U0101 & Circuit Tests) >> SFI System >> VC Output Circuit >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

VC Output Circuit: Procedure

  1. CHECK MIL 
    1. Check that Malfunction Indicator Lamp (MIL) lights up when turning the engine switch on (IG).

      OK

      MIL lights up.

    OK → SYSTEM OK 

    NG: Go to next step 

  2. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM 
    1. Connect Techstream to the DLC3.
    2. Turn the engine switch on (IG) and tester on.
    3. Check the communication between the tester and ECM.

      Result

      Result Proceed to
      Communication is possible A
      Communication is not possible B

    A → GO TO MIL CIRCUIT 

    B: Go to next step 

  3. CHECK THROTTLE BODY ASSEMBLY (CHECK MIL ILLUMINATED) 
    1. Disconnect the throttle body connector.
    2. Turn the engine switch on (IG).
    3. Check the MIL.

      Result

      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B
    4. Reconnect the throttle body connector.

    A → REPLACE THROTTLE BODY ASSEMBLY 

    B: Go to next step 

  4. CHECK ACCELERATOR PEDAL ASSEMBLY (CHECK MIL ILLUMINATED) 
    1. Disconnect the accelerator pedal position sensor connector.
    2. Turn the engine switch on (IG).
    3. Check the MIL.

      Result

      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B
    4. Reconnect the accelerator pedal position sensor connector.

    A → REPLACE ACCELERATOR PEDAL ASSEMBLY 

    B: Go to next step 

  5. CHECK VVT SENSOR FOR INTAKE CAMSHAFT BANK 1 (CHECK MIL ILLUMINATED) 
    1. Disconnect the VVT sensor for intake camshaft bank 1 connector.
    2. Turn the engine switch on (IG).
    3. Check the MIL.

      Result

      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B
    4. Reconnect the VVT sensor for intake camshaft bank 1 connector.

    A → REPLACE VVT SENSOR FOR INTAKE CAMSHAFT BANK 1 

    B: Go to next step 

  6. CHECK VVT SENSOR FOR EXHAUST CAMSHAFT BANK 1 (CHECK MIL ILLUMINATED) 
    1. Disconnect the VVT sensor for exhaust camshaft bank 1 connector.
    2. Turn the engine switch on (IG).
    3. Check the MIL.

      Result

      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B
    4. Reconnect the VVT sensor for exhaust camshaft bank 1 connector.

    A → REPLACE VVT SENSOR FOR EXHAUST CAMSHAFT BANK 1 

    B: Go to next step 

  7. CHECK VVT SENSOR FOR INTAKE CAMSHAFT BANK 2 (CHECK MIL ILLUMINATED) 
    1. Disconnect the VVT sensor for intake camshaft bank 2 connector.
    2. Turn the engine switch on (IG).
    3. Check the MIL.

      Result

      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B
    4. Reconnect the VVT sensor for intake camshaft bank 2 connector.

    A → REPLACE VVT SENSOR FOR INTAKE CAMSHAFT BANK 2 

    B: Go to next step 

  8. CHECK VVT SENSOR FOR EXHAUST CAMSHAFT BANK 2 (CHECK MIL ILLUMINATED) 
    1. Disconnect the VVT sensor for exhaust camshaft bank 2 connector.
    2. Turn the engine switch on (IG).
    3. Check the MIL.

      Result

      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B
    4. Reconnect the VVT sensor for exhaust camshaft bank 2 connector.

    A → REPLACE VVT SENSOR FOR EXHAUST CAMSHAFT BANK 2 

    B: Go to next step 

  9. CHECK FUEL PRESSURE SENSOR (CHECK MIL ILLUMINATED) 
    1. Disconnect the fuel pressure sensor connector.
    2. Turn the engine switch on (IG).
    3. Check the MIL.

      Result

      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B
    4. Reconnect the fuel pressure sensor connector.

    A → REPLACE FUEL PRESSURE SENSOR 

    B: Go to next step 

  10. CHECK CHARCOAL CANISTER ASSEMBLY (CHECK MIL ILLUMINATED) 
    1. Disconnect the canister pump module connector.
    2. Turn the engine switch on (IG).
    3. Check the MIL.

      Result

      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B
    4. Reconnect the canister pump module connector.

    A → REPLACE CHARCOAL CANISTER ASSEMBLY 

    B: Go to next step 

  11. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the throttle body connector.
      Fig 1: Identifying E3, E5 And A6 ECM Connector
      GTY146124Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the accelerator pedal position sensor connector.
    3. Disconnect the VVT sensor for intake camshaft bank 1 connector.
    4. Disconnect the VVT sensor for exhaust camshaft bank 1 connector.
    5. Disconnect the VVT sensor for intake camshaft bank 2 connector.
    6. Disconnect the VVT sensor for exhaust camshaft bank 2 connector.
    7. Disconnect the fuel pressure sensor connector.
    8. Disconnect the canister pump module connector.
    9. Disconnect the E3, E5 and A6 ECM connectors.
    10. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for short)

      Tester Connections Specified Conditions
      VC (E3-29) - Body ground 10 kΩ or higher
      VC2 (E5-29) - Body ground 10 kΩ or higher
      VCPA (A6-35) - Body ground 10 kΩ or higher
      VCP2 (A6-27) - Body ground 10 kΩ or higher
    11. Reconnect the ECM connectors.
    12. Reconnect the canister pump module connector.
    13. Reconnect the fuel pressure sensor connector.
    14. Reconnect the VVT sensor for exhaust camshaft bank 2 connector.
    15. Reconnect the VVT sensor for intake camshaft bank 2 connector.
    16. Reconnect the VVT sensor for exhaust camshaft bank 1 connector.
    17. Reconnect the VVT sensor for intake camshaft bank 1 connector.
    18. Reconnect the accelerator pedal position sensor connector.
    19. Reconnect the throttle body connector.

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → REPLACE ECM 

scientia non olet · About LEMON Manuals