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SFI SYSTEM VC Output Circuit

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DTC Code DTC Name
  VC Output Circuit
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DESCRIPTION

The ECM constantly generates a 5 V power supply voltage from the battery voltage supplied to the +B (BATT) terminal to operate the microprocessor. The ECM also provides this power source voltage to the sensors through the VC output circuit.

When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied with power through the VC circuit are inactivated because the power is not supplied from the VC circuit. Under this condition, the system does not start up and the MIL does not illuminate even if the system malfunctions.

Tip:

Under normal conditions, the MIL is illuminated for several seconds when the ignition switch is first turned to ON, and then goes off when the engine starts.

A01IO94E08
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WIRING DIAGRAM

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INSPECTION PROCEDURE

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PROCEDURE


  1. Click here

    CHECK MIL CONDITION


    1. Check that the Malfunction Indicator Lamp (MIL) lights up when turning the ignition switch to ON.

      OK
      MIL lights up.

  2. Click here

    CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Check for communication between the tester and ECM.

      Table 1. Result
      Result Proceed to
      Communication is possible A
      Communication is not possible B

  3. Click here

    CHECK MIL (THROTTLE POSITION SENSOR)


    1. Disconnect the throttle body assembly connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Table 2. Result
      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B

    4. Reconnect the throttle body assembly connector.


  4. Click here

    CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)


    1. Disconnect the accelerator pedal position sensor connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Table 3. Result
      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B

    4. Reconnect the accelerator pedal position sensor connector.


  5. Click here

    CHECK MIL (CAMSHAFT POSITION SENSOR (FOR INTAKE SIDE))


    1. Disconnect the camshaft position sensor (for intake side) connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Table 4. Result
      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B

    4. Reconnect the camshaft position sensor (for intake side) connector.


  6. Click here

    CHECK MIL (CAMSHAFT POSITION SENSOR (FOR EXHAUST SIDE))


    1. Disconnect the camshaft position sensor (for exhaust side) connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Table 5. Result
      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B

    4. Reconnect the camshaft position sensor (for exhaust side) connector.


  7. Click here

    CHECK MIL (VACUUM SENSOR)


    1. Disconnect the vacuum sensor connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Table 6. Result
      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B

    4. Reconnect the vacuum sensor connector.


  8. Click here

    CHECK MIL (OIL PRESSURE SENSOR)


    1. Disconnect the oil pressure sensor connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Table 7. Result
      Result Proceed to
      MIL illuminates A
      MIL does not illuminate B

    4. Reconnect the oil pressure sensor connector.


  9. Click here

    CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle body assembly connector.

    2. Disconnect the accelerator pedal position sensor connector.

    3. Disconnect the camshaft position sensor (for intake camshaft) connector.

    4. Disconnect the camshaft position sensor (for exhaust camshaft) connector.

    5. Disconnect the vacuum sensor connector.

    6. Disconnect the oil pressure sensor connector.

    7. Disconnect the ECM connectors.

    8. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      C68-89 (VCTA) - Body ground Always 10 kΩ or higher
      A51-57 (VCPA) - Body ground Always 10 kΩ or higher
      A51-58 (VCP2) - Body ground Always 10 kΩ or higher
      C68-119 (VCV1) - Body ground Always 10 kΩ or higher
      C68-121 (VCE1) - Body ground Always 10 kΩ or higher
      C68-67 (VCPM) - Body ground Always 10 kΩ or higher
      C68-95 (VCPT) - Body ground Always 10 kΩ or higher

    9. Reconnect the throttle body assembly connector.

    10. Reconnect the accelerator pedal position sensor connector.

    11. Reconnect the camshaft position sensor (for intake camshaft) connector.

    12. Reconnect the camshaft position sensor (for exhaust camshaft) connector.

    13. Reconnect the vacuum sensor connector.

    14. Reconnect the oil pressure sensor connector.

    15. Reconnect the ECM connectors.


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    SYSTEM OK

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    GO TO MIL CIRCUITClick here

  12. Click here

    REPLACE THROTTLE BODY ASSEMBLYClick here

  13. Click here

    REPLACE ACCELERATOR PEDAL ASSEMBLY (ACCELERATOR PEDAL POSITION SENSOR)Click here

  14. Click here

    REPLACE CAMSHAFT POSITION SENSOR (FOR INTAKE SIDE)Click here

  15. Click here

    REPLACE CAMSHAFT POSITION SENSOR (FOR EXHAUST SIDE)Click here

  16. Click here

    REPLACE VACUUM SENSORClick here

  17. Click here

    REPLACE OIL PRESSURE SENSORClick here

  18. Click here

    REPLACE ECMClick here

  19. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR