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Home >> Toyota >> 2021 >> Sequoia TRD Pro >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (3UR-FE) - Circuit Tests (2 Of 2) >> SFI System >> VC Output Circuit [08/2017 - 08/2019] >> Procedure
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VC Output Circuit [08/2017 - 08/2019]: Procedure

  1. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM 
    1. Connect the Techstream to the DLC3.
    2. Turn the ignition switch to ON.
    3. Turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine" item of the Data List.

      OK

      Communication is possible

    Result: 

    OK 

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE 

    Result: 

    NG 

    See step  2

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF EFI NO. 2) 
    1. Turn the ignition switch to ON.
      GTY763966Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage

      Tester Connection Switch Condition Specified Condition
      EFI NO. 2 fuse terminal - Body ground Ignition switch ON 11 to 14 V

      HINT: 

      • Check the fuse with it installed to the engine room relay block and junction block assembly.
      • If the result is not as specified, since current is not flowing to the +B and +B2 terminals of the ECM, the system may not be started.

    Result: 

    NG 

    GO TO ECM Power Source Circuit [08/2017 - 08/2019] 

    Result: 

    OK 

    See step  3

  3. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (THROTTLE POSITION SENSOR) 
    1. Disconnect the throttle body connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

      HINT: 

      Perform "Inspection After Repair" after replacing the throttle body (Refer to INITIALIZATION [08/2015 - 08/2019] ).

    Result: 

    A 

    REPLACE THROTTLE BODY ASSEMBLY 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  4

  4. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (ACCELERATOR PEDAL POSITION SENSOR) 
    1. Disconnect the accelerator pedal position sensor connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE ACCELERATOR PEDAL POSITION SENSOR 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  5

  5. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (CANISTER PUMP MODULE) 
    1. Disconnect the canister pump module connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE CANISTER PUMP MODULE 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  6

  6. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (AIR SWITCHING VALVE for Bank 1) 
    1. Disconnect the air switching valve (for Bank 1) connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE AIR SWITCHING VALVE 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  7

  7. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (AIR SWITCHING VALVE for Bank 2) 
    1. Disconnect the air switching valve (for Bank 2) connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE AIR SWITCHING VALVE 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  8

  8. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (POWER STEERING OIL PRESSURE SENSOR) 
    1. Disconnect the power steering oil pressure sensor connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE POWER STEERING OIL PRESSURE SENSOR 

    Result: 

    B 

    See step  9

  9. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (CAMSHAFT POSITION SENSOR) 
    1. Disconnect the camshaft position sensor connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE CAMSHAFT POSITION SENSOR 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  10

  10. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (CRANKSHAFT POSITION SENSOR) 
    1. Disconnect the crankshaft position sensor connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE CRANKSHAFT POSITION SENSOR 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  11

  11. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (VVT SENSOR for Intake Side of Bank 1) 
    1. Disconnect the VVT sensor (for Intake Side of Bank 1) connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE VVT SENSOR (for Intake Side of Bank 1) 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  12

  12. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (VVT SENSOR for Exhaust Side of Bank 1) 
    1. Disconnect the VVT sensor (for Exhaust Side of Bank 1) connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE VVT SENSOR (for Exhaust Side of Bank 1) 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  13

  13. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (VVT SENSOR for Intake Side of Bank 2) 
    1. Disconnect the VVT sensor (for Intake Side of Bank 2) connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE VVT SENSOR (for Intake Side of Bank 2) 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  14

  14. CHECK CONNECTION BETWEEN TECHSTREAM AND ECM (VVT SENSOR for Exhaust Side of Bank 2) 
    1. Disconnect the VVT sensor (for Exhaust Side of Bank 2) connector.
    2. Connect the Techstream to the DLC3.
    3. Turn the ignition switch to ON and turn the Techstream on.
    4. Check the communication between the Techstream and ECM.

      HINT: 

      It can be checked using the "Engine and ECT" item of the Data List.

      RESULT

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

    Result: 

    A 

    REPLACE VVT SENSOR (for Exhaust Side of Bank 2) 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    B 

    See step  15

  15. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the throttle body connector.
    2. Disconnect the accelerator pedal position sensor connector.
    3. Disconnect the canister pump module connector.
    4. Disconnect the air switching valve (for Bank 1) connector.
    5. Disconnect the air switching valve (for Bank 2) connector.
    6. Disconnect the power steering oil pressure sensor connector.
    7. Disconnect the camshaft position sensor connector.
    8. Disconnect the crankshaft position sensor connector.
    9. Disconnect the VVT sensor (for Intake Side of Bank 1) connector.
    10. Disconnect the VVT sensor (for Exhaust Side of Bank 1) connector.
    11. Disconnect the VVT sensor (for Intake Side of Bank 2) connector.
    12. Disconnect the VVT sensor (for Exhaust Side of Bank 2) connector.
    13. Disconnect the integration relay connector.
    14. Disconnect the ECM connectors.
    15. Measure the resistance according to the value(s) in the table below.

      Standard resistance

      Tester Connection Condition Specified Condition
      D56-125 (VCTA) - Body ground Always 10 kΩ or higher
      A27-55 (VCPA) - Body ground Always 10 kΩ or higher
      A27-58 (VCP2) - Body ground Always 10 kΩ or higher
      D56-110 (VCV2) - Body ground Always 10 kΩ or higher
      D56-87 (VCV1) - Body ground Always 10 kΩ or higher
      D56-75 (VCAI) - Body ground Always 10 kΩ or higher
      D56-102 (VCCP) - Body ground Always 10 kΩ or higher
      A27-2 (+B) - Body ground Always 10 kΩ or higher
      A27-3 (+B2) - Body ground Always 10 kΩ or higher
      A27-2 (+B) - 2B-4 Always Below 1 Ω
      A27-3 (+B2) - 2B-4 Always Below 1 Ω

    Result: 

    OK 

    REPLACE ECM 

    (Refer to REMOVAL [08/2015 - ] )

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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