SFI SYSTEM VC Output Circuit

DESCRIPTION

The ECM constantly uses 5 V 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.

A019LZWE05

When the VC circuit is shorted, the microprocessor in the ECM and sensors that are supplied 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 turned on (IG). The MIL goes off when the engine is started.

WIRING DIAGRAM

A019K4TE02
A019MD0E02

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK MIL


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

      OK
      MIL illuminates.

    NG

    CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM Click here

    OK

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

  2. CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    3. Turn the tester on.

    4. Check the communication between the tester 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 position sensor connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    4. Reconnect the throttle position sensor connector.


    B

    REPLACE THROTTLE WITH MOTOR BODY 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 A
      MIL illuminates B

    4. Reconnect the accelerator pedal sensor assembly connector.


    B

    REPLACE ACCELERATOR PEDAL ASSEMBLY Click here

    A

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


    1. Disconnect the VVT sensor for intake side bank 1 connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    4. Reconnect the VVT sensor for intake side bank 1 connector.


    B

    REPLACE VVT SENSOR FOR INTAKE SIDE BANK 1 Click here

    A

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


    1. Disconnect the VVT sensor for intake side bank 2 connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    4. Reconnect the VVT sensor for intake side bank 2 connector.


    B

    REPLACE VVT SENSOR FOR INTAKE SIDE BANK 2 Click here

    A

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


    1. Disconnect the VVT sensor for exhaust side bank 1 connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    4. Reconnect the VVT sensor for exhaust side bank 1 connector.


    B

    REPLACE VVT SENSOR FOR EXHAUST SIDE BANK 1 Click here

    A

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


    1. Disconnect the VVT sensor for exhaust side bank 2 connector.

    2. Turn the engine switch on (IG).

    3. Check the MIL.

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

    4. Reconnect the VVT sensor for exhaust side bank 2 connector.


    B

    REPLACE VVT SENSOR FOR EXHAUST SIDE BANK 2 Click here

    A

  9. CHECK HARNESS AND CONNECTOR (THROTTLE POSITION SENSOR - ECM)


    1. Disconnect the throttle position sensor connector.

      A019MDRE14

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D1-80 (VCTA) or D28-5 (VC) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Throttle Position Sensor)

      		 *2

      Front view of wire harness connector

      (to ECM)

    4. Reconnect the throttle position sensor connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (THROTTLE POSITION SENSOR - ECM)

    OK

  10. CHECK HARNESS AND CONNECTOR (ACCELERATOR PEDAL SENSOR ASSEMBLY - ECM)


    1. Disconnect the accelerator pedal sensor assembly connector.

      A019MVAE09

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A46-1 (VCP2) or A43-59 (VCP2) - Body ground Always 10 kΩ or higher
      A46-4 (VCPA) or A43-57 (VCPA) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Accelerator Pedal Sensor Assembly)

      		 *2

      Front view of wire harness connector

      (to ECM)

    4. Reconnect the accelerator pedal sensor assembly connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (ACCELERATOR PEDAL SENSOR ASSEMBLY - ECM)

    OK

  11. CHECK HARNESS AND CONNECTOR (VVT SENSOR FOR INTAKE SIDE BANK 2 - ECM)


    1. Disconnect the VVT sensor for intake side bank 2 connector.

      A019OOOE37

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D23-3 (VC) or D1-66 (VCV2) - Body ground Always 10 kΩ or higher
      Text in Illustration
      *1

      Front view of wire harness connector

      (to VVT Sensor for Intake Side Bank 2)

      		 *2

      Front view of wire harness connector

      (to ECM)

    4. Reconnect the VVT sensor for intake side bank 2 connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (VVT SENSOR FOR INTAKE SIDE BANK 2 - ECM)

    OK

  12. CHECK HARNESS AND CONNECTOR (VCV1 CIRCUIT)


    1. Disconnect the VVT sensor for intake side bank 1 connector.

    2. Disconnect the VVT sensor for exhaust side bank 1 connector.

    3. Disconnect the VVT sensor for exhaust side bank 2 connector.

    4. Disconnect the ECM connector.

    5. A019OYQE34
      Text in Illustration
      *1

      Front view of wire harness connector

      (to ECM)

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D1-67 (VCV1) - Body ground Always 10 kΩ or higher

    6. Reconnect the VVT sensor for exhaust side bank 2 connector.

    7. Reconnect the VVT sensor for exhaust side bank 1 connector.

    8. Reconnect the VVT sensor for intake side bank 1 connector.

    9. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here