SFI SYSTEM VC Output Circuit

DESCRIPTION

The ECM constantly generates 5 V of 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.

A01DQWLE14

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. The MIL goes off when the engine is started.

WIRING DIAGRAM

A01DQLUE06
A01DR1XE02

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK MIL


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

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

    A

    SYSTEM OK

    B

  2. CHECK COMMUNICATION BETWEEN INTELLIGENT TESTER AND ECM


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and tester on.

    3. 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 BODY WITH MOTOR ASSEMBLY)


    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 Click here

    B

  4. 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.

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

    4. Reconnect the accelerator pedal position sensor connector.


    A

    REPLACE ACCELERATOR PEDAL ASSEMBLY Click here

    B

  5. CHECK MIL (VVT SENSOR FOR INTAKE SIDE OF BANK 1)


    1. Disconnect the VVT sensor (for Intake Side of Bank 1) 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 VVT sensor (for Intake Side of Bank 1) connector.


    A

    REPLACE VVT SENSOR (INTAKE SIDE OF BANK 1) Click here

    B

  6. CHECK MIL (VVT SENSOR FOR INTAKE SIDE OF BANK 2)


    1. Disconnect the VVT sensor (for Intake Side of Bank 2) 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 VVT sensor (for Intake Side of Bank 2) connector.


    A

    REPLACE VVT SENSOR (INTAKE SIDE OF BANK 2) Click here

    B

  7. CHECK MIL (VVT SENSOR FOR EXHAUST SIDE OF BANK 1)


    1. Disconnect the VVT sensor (for Exhaust Side of Bank 1) 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 VVT sensor (for Exhaust Side of Bank 1) connector.


    A

    REPLACE VVT SENSOR (EXHAUST SIDE OF BANK 1) Click here

    B

  8. CHECK MIL (VVT SENSOR FOR EXHAUST SIDE OF BANK 2)


    1. Disconnect the VVT sensor (for Exhaust Side of Bank 2) 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 VVT sensor (for Exhaust Side of Bank 2) connector.


    A

    REPLACE VVT SENSOR (EXHAUST SIDE OF BANK 2) Click here

    B

  9. CHECK MIL (POWER STEERING OIL PRESSURE SWITCH)


    1. Disconnect the power steering oil pressure switch 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 power steering oil pressure switch connector.


    A

    REPLACE POWER STEERING OIL PRESSURE SWITCH Click here

    B

  10. CHECK MIL (EMISSION CONTROL VALVE SET)


    1. Disconnect the emission control valve set 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 emission control valve set connector.


    A

    REPLACE EMISSION CONTROL VALVE SET Click here

    B

  11. CHECK MIL (NO. 2 EMISSION CONTROL VALVE SET)


    1. Disconnect the No. 2 emission control valve set 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 No. 2 emission control valve set connector.


    A

    REPLACE NO. 2 EMISSION CONTROL VALVE SET Click here

    B

  12. CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle body with motor assembly connector.

    2. Disconnect the accelerator pedal position sensor connector.

    3. Disconnect the VVT sensor (for Intake Side of Bank 1) connector.

    4. Disconnect the VVT sensor (for Intake Side of Bank 2) connector.

    5. Disconnect the VVT sensor (for Exhaust Side of Bank 1) connector.

    6. Disconnect the VVT sensor (for Exhaust Side of Bank 2) connector.

    7. Disconnect the emission control valve set connector.

    8. Disconnect the No. 2 emission control valve set connector.

    9. Disconnect the power steering oil pressure switch connector.

    10. Disconnect the ECM connectors.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      G56-4 (VCPA) - Body ground Always 10 kΩ or higher
      G56-2 (VCP2) - Body ground Always 10 kΩ or higher
      C36-13 (VCTA) - Body ground Always 10 kΩ or higher
      C34-15 (VCV1) - Body ground Always 10 kΩ or higher
      C34-16 (VCV2) - Body ground Always 10 kΩ or higher

    12. Reconnect the ECM connectors.

    13. Reconnect the throttle body with motor assembly connector.

    14. Reconnect the accelerator pedal position sensor connector.

    15. Reconnect the VVT sensor (for Intake Side of Bank 1) connector.

    16. Reconnect the VVT sensor (for Intake Side of Bank 2) connector.

    17. Reconnect the VVT sensor (for Exhaust Side of Bank 1) connector.

    18. Reconnect the VVT sensor (for Exhaust Side of Bank 2) connector.

    19. Reconnect the emission control valve set connector.

    20. Reconnect the No. 2 emission control valve set connector.

    21. Reconnect the power steering oil pressure switch connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here