SFI SYSTEM VC Output Circuit

DESCRIPTION

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

A01VJM8E01

When the VC circuit is short-circuited, the microprocessor in the ECM and sensors that are supplied with power through the VC circuit are deactivated 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.

Tech Tips

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

WIRING DIAGRAM

A01VHN3E01

CAUTION / NOTICE / HINT

Note

Perform electronic throttle learning after replacing the ECM or throttle with motor body assembly Click here.

PROCEDURE


  1. CHECK MIL CONDITION


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

      OK
      MIL illuminates.

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

  2. 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.

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

    B

    CHECK MIL CIRCUIT Click here

    A

  3. CHECK MIL (THROTTLE POSITION SENSOR)


    1. Disconnect the throttle with motor body assembly connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Result
      Result Proceed to
      MIL does not illuminate A
      MIL illuminates B

    B

    REPLACE THROTTLE WITH MOTOR BODY ASSEMBLY Click here

    A

  4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)


    1. Disconnect the accelerator pedal sensor assembly connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Result
      Result Proceed to
      MIL does not illuminate A
      MIL illuminates B

    B

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

    A

  5. CHECK MIL (CAMSHAFT POSITION SENSOR)


    1. Disconnect the camshaft position sensor connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

      Result
      Result Proceed to
      MIL does not illuminate A
      MIL illuminates B

    B

    REPLACE CAMSHAFT POSITION SENSOR Click here

    A

  6. CHECK MIL (MANIFOLD ABSOLUTE PRESSURE SENSOR)


    1. Disconnect the manifold absolute pressure sensor connector.

    2. Turn the ignition to ON.

    3. Check the MIL.

      Result
      Result Proceed to
      MIL does not illuminate A
      MIL illuminate B

    B

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    A

  7. CHECK HARNESS AND CONNECTOR (EACH SENSOR - ECM)


    1. Disconnect the throttle with motor body assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

    3. Disconnect the camshaft position sensor connector.

    4. Disconnect the manifold absolute pressure sensor connector.

    5. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B87-55 (VCTA) - Body ground Always 10 kΩ or higher
      A71-11 (VCPA) - Body ground Always 10 kΩ or higher
      A71-19 (VCP2) - Body ground Always 10 kΩ or higher
      B87-80 (VC) - Body ground Always 10 kΩ or higher
      B87-54 (VCPM) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR