SFI SYSTEM VC Output Circuit

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.

A01DQWLE15

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

WIRING DIAGRAM

A01DP92E01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK MIL CONDITION


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

      OK
      MIL lights up.

    NG

    CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM Click here

    OK

    SYSTEM OK

  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 the communication between the tester and ECM.

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

    A

    GO TO MIL CIRCUIT Click here

    B

  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 illuminates A
      MIL does not illuminate B

    4. Reconnect the throttle body with motor assembly connector.


    A

    REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY (THROTTLE POSITION SENSOR) Click here

    B

  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 illuminates A
      MIL does not illuminate B

    4. Reconnect the accelerator pedal sensor assembly connector.


    A

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

    B

  5. CHECK MIL (AIR PRESSURE SENSOR)


    1. Disconnect the air pressure sensor connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    4. Reconnect the air pressure sensor connector.


    A

    REPLACE AIR PRESSURE SENSOR Click here

    B

  6. CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle body with motor assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

    3. Disconnect the air pressure sensor connector.

    4. Disconnect the ECM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C61-10 (VCTA) - Body ground Always 10 kΩ or higher
      G60-4 (VCPA) - Body ground Always 10 kΩ or higher
      G60-3 (VCP2) - Body ground Always 10 kΩ or higher
      C62-6 (VC) - Body ground Always 10 kΩ or higher

    6. Reconnect the throttle body with motor assembly connector.

    7. Reconnect the accelerator pedal sensor assembly connector.

    8. Reconnect the air pressure sensor connector.

    9. Reconnect the ECM connectors.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here