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.

A01X0NGE65

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 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

A01X31JE01
B00200ZE01

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 GTS AND ECM


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON and turn the GTS on.

    3. Check the communication between the GTS 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

    A

    REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY Click here

    B

  4. CHECK MIL (ACCELERATOR PEDAL SENSOR ASSEMBLY)


    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

    A

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

    B

  5. CHECK MIL (NO. 1 EMISSION CONTROL VALVE SET)


    1. Disconnect the No. 1 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

    A

    REPLACE NO. 1 EMISSION CONTROL VALVE SET Click here

    B

  6. 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

    A

    REPLACE NO. 2 EMISSION CONTROL VALVE SET Click here

    B

  7. 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

    A

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

    B

  8. 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

    A

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

    B

  9. 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

    A

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

    B

  10. 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

    A

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

    B

  11. CHECK MIL (POWER STEERING OIL PRESSURE SENSOR)


    1. Disconnect the power steering oil 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

    A

    REPLACE POWER STEERING OIL PRESSURE SENSOR Click here

    B

  12. CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle body with motor assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

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

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

    5. Disconnect the VVT sensor (for intake side of bank 1) connector.

    6. Disconnect the VVT sensor (for intake side of bank 2) connector.

    7. Disconnect the VVT sensor (for exhaust side of bank 1) connector.

    8. Disconnect the VVT sensor (for exhaust side of bank 2) connector.

    9. Disconnect the power steering oil pressure sensor connector.

    10. Disconnect the ECM connectors.

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

      Standard Resistance
      for LHD
      Tester Connection Condition Specified Condition
      A38-57 (VCPA) - Body ground Always 10 kΩ or higher
      A38-59 (VCP2) - Body ground Always 10 kΩ or higher
      C45-80 (VCTA) - Body ground Always 10 kΩ or higher
      C45-67 (VCV1) - Body ground Always 10 kΩ or higher
      C45-66 (VCV2) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      A52-57 (VCPA) - Body ground Always 10 kΩ or higher
      A52-59 (VCP2) - Body ground Always 10 kΩ or higher
      C46-80 (VCTA) - Body ground Always 10 kΩ or higher
      C46-67 (VCV1) - Body ground Always 10 kΩ or higher
      C46-66 (VCV2) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR