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.

B00203HE45

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


B001XGOE02
B001YZAE02

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 engine switch on (IG) and GTS on.

    3. Check the communication between the GTS and ECM.

      Tech Tips

      It can be checked using the "Engine" 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 engine switch on (IG).

    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 Engine switch on (IG) 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 CONNECTION BETWEEN GTS AND ECM (THROTTLE POSITION SENSOR)


    1. Disconnect the throttle body connector.

    2. Turn the engine switch on (IG).

    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 ASSEMBLY Click here

    A

  4. CHECK CONNECTION BETWEEN GTS AND ECM (ACCELERATOR PEDAL POSITION SENSOR)


    1. Disconnect the accelerator pedal position sensor connector.

    2. Turn the engine switch on (IG).

    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 CONNECTION BETWEEN GTS AND ECM (MANIFOLD ABSOLUTE PRESSURE SENSOR)


    1. Disconnect the manifold absolute pressure sensor connector.

    2. Turn the engine switch on (IG).

    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 MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    A

  6. CHECK CONNECTION BETWEEN GTS AND ECM (AIR SWITCHING VALVE for Bank 1)


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

    2. Turn the engine switch on (IG).

    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 AIR SWITCHING VALVE Click here

    A

  7. CHECK CONNECTION BETWEEN GTS AND ECM (AIR SWITCHING VALVE for Bank 2)


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

    2. Turn the engine switch on (IG).

    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 AIR SWITCHING VALVE Click here

    A

  8. CHECK CONNECTION BETWEEN GTS AND ECM (POWER STEERING OIL PRESSURE SENSOR)


    1. Disconnect the power steering oil pressure sensor connector.

    2. Turn the engine switch on (IG).

    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

  9. CHECK CONNECTION BETWEEN GTS AND ECM (CAMSHAFT POSITION SENSOR)


    1. Disconnect the camshaft position sensor connector.

    2. Turn the engine switch on (IG).

    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 CAMSHAFT POSITION SENSOR Click here

    A

  10. CHECK CONNECTION BETWEEN GTS AND ECM (CRANKSHAFT POSITION SENSOR)


    1. Disconnect the crankshaft position sensor connector.

    2. Turn the engine switch on (IG).

    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 CRANKSHAFT POSITION SENSOR Click here

    A

  11. CHECK CONNECTION BETWEEN GTS AND ECM (VVT SENSOR for Intake Side of Bank 1)


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

    2. Turn the engine switch on (IG).

    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

  12. CHECK CONNECTION BETWEEN GTS AND ECM (VVT SENSOR for Exhaust Side of Bank 1)


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

    2. Turn the engine switch on (IG).

    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

  13. CHECK CONNECTION BETWEEN GTS AND ECM (VVT SENSOR for Intake Side of Bank 2)


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

    2. Turn the engine switch on (IG).

    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

  14. CHECK CONNECTION BETWEEN GTS AND ECM (VVT SENSOR for Exhaust Side of Bank 2)


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

    2. Turn the engine switch on (IG).

    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

  15. CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle body connector.

    2. Disconnect the accelerator pedal position sensor connector.

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

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

    5. Disconnect the power steering oil pressure switch connector.

    6. Disconnect the camshaft position sensor connector.

    7. Disconnect the crankshaft position sensor connector.

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

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

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

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

    12. Disconnect the manifold absolute pressure sensor connector.

    13. Disconnect the ECM connectors.

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

      Standard Resistance
      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
      C46-66 (VCV2) - Body ground Always 10 kΩ or higher
      C46-67 (VCV1) - 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
      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
      C45-66 (VCV2) - Body ground Always 10 kΩ or higher
      C45-67 (VCV1) - 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

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR