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.

A015D95E65

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 engine switch is first turned on (IG). The MIL goes off when the engine is started.

WIRING DIAGRAM

A01574LE03
A0158CXE03

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK MIL


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

      OK
      MIL lights up

    NG

    CHECK COMMUNICATION BETWEEN GTS AND ECM Click here

    OK

    SYSTEM OK

  2. CHECK COMMUNICATION BETWEEN GTS AND ECM


    1. Connect the GTS to the DLC3.

    2. Turn the engine switch on (IG) 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 POSITION SENSOR)


    1. Disconnect the C3 throttle body connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE THROTTLE BODY ASSEMBLY Click here

    B

  4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)


    1. Disconnect the A31 accelerator pedal position sensor connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE ACCELERATOR PEDAL POSITION SENSOR Click here

    B

  5. CHECK MIL (POWER STEERING OIL PRESSURE SENSOR)


    1. Disconnect the C59 power steering oil pressure sensor connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE POWER STEERING OIL PRESSURE SENSOR Click here

    B

  6. CHECK MIL (CAMSHAFT POSITION SENSOR)


    1. Disconnect the C99 camshaft position sensor connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE CAMSHAFT POSITION SENSOR Click here

    B

  7. CHECK MIL (CRANKSHAFT POSITION SENSOR)


    1. Disconnect the C114 crankshaft position sensor connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE CRANKSHAFT POSITION SENSOR Click here

    B

  8. CHECK MIL (VVT SENSOR for Intake Side of Bank 1)


    1. Disconnect the C100 VVT sensor (for Intake Side of Bank 1) connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE VVT SENSOR (for Intake Side of Bank 1) Click here

    B

  9. CHECK MIL (VVT SENSOR for Exhaust Side of Bank 1)


    1. Disconnect the C121T sensor (for Exhaust Side of Bank 1) connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE VVT SENSOR (for Exhaust Side of Bank 1) Click here

    B

  10. CHECK MIL (VVT SENSOR for Intake Side of Bank 2)


    1. Disconnect the C101 VVT sensor (for Intake Side of Bank 2) connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE VVT SENSOR (for Intake Side of Bank 2) Click here

    B

  11. CHECK MIL (VVT SENSOR for Exhaust Side of Bank 2)


    1. Disconnect the C122T sensor (for Exhaust Side of Bank 2) connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    A

    REPLACE VVT SENSOR (for Exhaust Side of Bank 2) Click here

    B

  12. CHECK HARNESS AND CONNECTOR


    1. Disconnect the C3 throttle body connector.

    2. Disconnect the A31 accelerator pedal position sensor connector.

    3. Disconnect the C59 power steering oil pressure sensor connector.

    4. Disconnect the C99 camshaft position sensor connector.

    5. Disconnect the C114 crankshaft position sensor connector.

    6. Disconnect the C100 VVT sensor (for Intake Side of Bank 1) connector.

    7. Disconnect the C121 VVT sensor (for Exhaust Side of Bank 1) connector.

    8. Disconnect the C101 VVT sensor (for Intake Side of Bank 2) connector.

    9. Disconnect the C122 VVT sensor (for Exhaust Side of Bank 2) connector.

    10. Disconnect the ECM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C45-80 (VCTA) - Body ground Always 10 kΩ or higher
      A38-57 (VCPA) - Body ground Always 10 kΩ or higher
      A38-59 (VCP2) - Body ground Always 10 kΩ or higher
      C45-66 (VCV2) - Body ground Always 10 kΩ or higher
      C45-67 (VCV1) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here