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.

A002BWTE33

When the VC circuit has a short circuit, the microprocessor in the ECM and sensors that are supplied power through the VC circuit are deactivated because power is not supplied from the VC circuit. When the system is in this condition, it will not start.

WIRING DIAGRAM

A00286BE09
*a Camshaft Position Sensor (for Intake Camshaft)
*b Camshaft Position Sensor (for Exhaust Camshaft)
*c Intake Air Control Valve Actuator (for Tumble Control Valve)
*d OUT
A002AK5E22
*a Throttle Body with Motor Assembly
*b Accelerator Pedal Sensor Assembly

PROCEDURE


  1. CHECK COMMUNICATION BETWEEN GTS AND ECM


    1. Connect the GTS to the DLC3.

    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

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

    A

  2. CHECK EFI NO. 2 FUSE VOLTAGE

    A00281UC03
    *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
    *2 EFI NO. 2 Fuse

    1. 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


      • Check the fuse with it installed to the No. 1 engine room relay block and No. 1 junction block assembly.

      • 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.

      Result
      Proceed to
      OK
      NG

    NG

    GO TO ECM POWER SOURCE CIRCUIT

    OK

  3. CHECK CONNECTION BETWEEN GTS AND ECM (THROTTLE POSITION SENSOR)


    1. Disconnect the throttle body with motor assembly connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between GTS and ECM.

      Tech Tips

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

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

      Tech Tips

      Perform "Inspection After Repair" after replacing the throttle body with motor assembly.

      Click here


    B

    REPLACE THROTTLE BODY WITH MOTOR ASSEMBLY Click here

    A

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


    1. Disconnect the accelerator pedal sensor assembly connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between GTS and ECM.

      Tech Tips

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

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

    B

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

    A

  5. CHECK CONNECTION BETWEEN GTS AND ECM (INTAKE AIR CONTROL VALVE ACTUATOR (FOR TUMBLE CONTROL VALVE))


    1. Disconnect the intake air control valve actuator (for tumble control valve) connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between GTS and ECM.

      Tech Tips

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

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

    B

    REPLACE INTAKE AIR CONTROL VALVE ACTUATOR (FOR TUMBLE CONTROL VALVE) Click here

    A

  6. CHECK CONNECTION BETWEEN GTS AND ECM (CAMSHAFT POSITION SENSOR FOR INTAKE CAMSHAFT)


    1. Disconnect the camshaft position sensor (for intake camshaft) connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between GTS and ECM.

      Tech Tips

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

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

    B

    REPLACE CAMSHAFT POSITION SENSOR (FOR INTAKE CAMSHAFT) Click here

    A

  7. CHECK CONNECTION BETWEEN GTS AND ECM (CAMSHAFT POSITION SENSOR FOR EXHAUST CAMSHAFT)


    1. Disconnect the camshaft position sensor (for exhaust camshaft) connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between GTS and ECM.

      Tech Tips

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

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

    B

    REPLACE CAMSHAFT POSITION SENSOR (FOR EXHAUST CAMSHAFT) Click here

    A

  8. CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle body with motor assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

    3. Disconnect the intake air control valve actuator (for tumble control valve) connector.

    4. Disconnect the camshaft position sensor (for intake camshaft) connector.

    5. Disconnect the camshaft position sensor (for exhaust camshaft) connector.

    6. Disconnect the ECM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      C1-125 (VCTA) - Body ground Always 10 kΩ or higher
      A43-53 (VCPA) - Body ground Always 10 kΩ or higher
      A43-56 (VCP2) - Body ground Always 10 kΩ or higher
      C1-130 (VCIA) - Body ground Always 10 kΩ or higher
      C1-111 (VCE1) - Body ground Always 10 kΩ or higher
      C1-113 (VCV1) - Body ground Always 10 kΩ or higher
      2 (EFI No. 2 fuse) - A43-2 (+B) Always Below 1 Ω
      2 (EFI No. 2 fuse) - A43-3 (+B2) Always Below 1 Ω
      A43-2 (+B) - Body ground Always 10 kΩ or higher
      A43-3 (+B2) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR