SFI SYSTEM VC Output Circuit

DESCRIPTION

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

A01ELNVE53

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.

Tech Tips

Under normal conditions, the MIL is illuminated when the ignition switch is turned to ON. The MIL turns off when the engine is started.

WIRING DIAGRAM

A01ELRRE03
A01EJ0VE20

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK MIL


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

      OK
      MIL turns on.

    NG

    CHECK COMMUNICATION BETWEEN GTS AND ECM Click here

    OK

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

  2. CHECK COMMUNICATION BETWEEN GTS AND ECM


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

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

    B

    GO TO MIL CIRCUIT Click here

    A

  3. CHECK MIL (THROTTLE POSITION SENSOR)


    1. Disconnect the throttle body with motor 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 BODY WITH MOTOR ASSEMBLY Click here

    A

  4. CHECK MIL (ACCELERATOR PEDAL SENSOR ASSEMBLY)


    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 (FOR INTAKE CAMSHAFT))


    1. Disconnect the camshaft position sensor (for intake camshaft) 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 (FOR INTAKE CAMSHAFT) Click here

    A

  6. CHECK MIL (CAMSHAFT POSITION SENSOR (FOR EXHAUST CAMSHAFT))


    1. Disconnect the camshaft position sensor (for exhaust camshaft) 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 (FOR EXHAUST CAMSHAFT) Click here

    A

  7. CHECK MIL (INTAKE AIR CONTROL VALVE ACTUATOR)


    1. Disconnect the intake air control valve actuator 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 INTAKE AIR CONTROL VALVE ACTUATOR Click here

    A

  8. CHECK HARNESS AND CONNECTOR (VC CIRCUIT)


    1. Disconnect the throttle body with motor assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

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

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

    5. Disconnect the intake air control valve actuator connector.

    6. Disconnect the ECM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-57 (VCPA) - Body ground Always 10 kΩ or higher
      A49-58 (VCP2) - Body ground Always 10 kΩ or higher
      B58-72 (VCIA) - Body ground Always 10 kΩ or higher
      B58-88 (VCTA) - Body ground Always 10 kΩ or higher
      B58-98 (VCE1) - Body ground Always 10 kΩ or higher
      B58-99 (VCV1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here