SFI SYSTEM VC Output Circuit

DESCRIPTION

The ECM constantly generates a 5 V power source 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.

A01VZ5YE45

When the VC circuit is short-circuited, the microprocessor in the ECM and the sensors that are supplied with power through the VC circuit are inactivated because 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 engine switch is turned on (IG). The MIL goes off when the engine is started.

WIRING DIAGRAM

A01W0ZME03
A01VZZDE09
*a Throttle Body with Motor Assembly
*b Accelerator Pedal Sensor Assembly

PROCEDURE


  1. CHECK MIL


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

      OK
      MIL lights up.

    OK

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

    NG

  2. CHECK COMMUNICATION BETWEEN GTS AND ECM


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG).

    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 engine switch on (IG).

    3. Check the MIL.

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

      Tech Tips

      Perform "Inspection After Repair" after replacing the throttle body with motor assembly Click here.


    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 engine switch on (IG).

    3. Check the MIL.

      Result
      Result Proceed to
      MIL does not illuminate (w/ tumble control valve) A
      MIL illuminates B
      MIL does not illuminate (w/o tumble control valve) C

    B

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

    C

    CHECK MIL (CAMSHAFT POSITION SENSOR (FOR INTAKE CAMSHAFT)) Click here

    A

  5. CHECK MIL (INTAKE AIR CONTROL VALVE ACTUATOR (FOR TUMBLE CONTROL VALVE))


    1. Disconnect the intake air control valve actuator (for tumble control valve) connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    B

    REPLACE INTAKE AIR CONTROL VALVE ACTUATOR (FOR TUMBLE CONTROL VALVE) Click here

    A

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


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

    2. Turn the engine switch on (IG).

    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

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


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

    2. Turn the engine switch on (IG).

    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

  8. CHECK HARNESS AND CONNECTOR


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

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

    3. Disconnect the throttle body with motor assembly connector.

    4. Disconnect the intake air control valve actuator (for tumble control valve) connector*.


      • *: w/ tumble control valve.

    5. Disconnect the accelerator pedal sensor assembly 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
      D70-111 (VCE1) - Body ground Always 10 kΩ or higher
      D70-113 (VCV1) - Body ground Always 10 kΩ or higher
      D70-125 (VCTA) - Body ground Always 10 kΩ or higher
      D70-130 (VCIA)* - Body ground Always 10 kΩ or higher
      A64-53 (VCPA) - Body ground Always 10 kΩ or higher
      A64-56 (VCP2) - Body ground Always 10 kΩ or higher

      • *: w/ tumble control valve.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR