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.

B00203HE46

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.

WIRING DIAGRAM


B001XVBE01
B00200ZE01

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. READ VALUE USING GTS


    1. Connect the GTS to the DLC3.

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

    3. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

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

    A

  2. CHECK TERMINAL VOLTAGE (POWER SOURCE OF ECM)


    1. B001Z90E01
      Text Illustration
      *1 Engine Room Relay Block
      *2 EFI No. 2 Fuse

      Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1 (EFI No. 2 fuse) - Body ground Ignition switch ON 11 to 14 V

      Tech Tips

      If the result is not as specified, since current is not flowing to the +B and +B2 terminals of the ECM, the system may not be started.


    NG

    GO TO ECM POWER SOURCE CIRCUIT Click here

    OK

  3. CHECK MIL (THROTTLE POSITION SENSOR)


    1. Disconnect the throttle body with motor connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

    REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY Click here

    A

  4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)


    1. Disconnect the accelerator pedal position sensor connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

    REPLACE ACCELERATOR PEDAL POSITION SENSOR Click here

    A

  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. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

    REPLACE NO. 1 EMISSION CONTROL VALVE SET Click here

    A

  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. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

    REPLACE NO. 2 EMISSION CONTROL VALVE SET Click here

    A

  7. CHECK MIL (POWER STEERING OIL PRESSURE SENSOR)


    1. Disconnect the power steering oil pressure sensor connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

    REPLACE POWER STEERING OIL PRESSURE SENSOR Click here

    A

  8. 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. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

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

    A

  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. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

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

    A

  10. 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. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

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

    A

  11. 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. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine and ECT" item of the Data List.

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

    B

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

    A

  12. CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle body connector.

    2. Disconnect the accelerator pedal position sensor connector.

    3. Disconnect the air switching valve (for Bank 1) connector.

    4. Disconnect the air switching valve (for Bank 2) connector.

    5. Disconnect the power steering oil pressure sensor connector.

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

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

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

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

    10. Disconnect the ECM connectors.

    11. Disconnect the No. 1 integration relay connectors.

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

      Standard Resistance
      for LHD
      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
      C45-67 (VCV1) - Body ground Always 10 kΩ or higher
      C45-66 (VCV2) - Body ground Always 10 kΩ or higher
      1S-11 - A38-3 (+B) Always Below 1 Ω
      1S-11 - A38-2 (+B2) Always Below 1 Ω
      1S-11 or A38-3 (+B) - Body ground Always 10 kΩ or higher
      1S-11 or A38-2 (+B2) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      C46-80 (VCTA) - Body ground Always 10 kΩ or higher
      A52-57 (VCPA) - Body ground Always 10 kΩ or higher
      A52-59 (VCP2) - 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
      1S-11 - A52-3 (+B) Always Below 1 Ω
      1S-11 - A52-2 (+B2) Always Below 1 Ω
      1S-11 or A52-3 (+B) - Body ground Always 10 kΩ or higher
      1S-11 or A52-2 (+B2) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR