SFI SYSTEM(w/o Canister Pump Module) 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.

A01QPTDE23

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 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

A01QT45E01
*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
A01QOF6E10
*a Throttle with Motor Body Assembly
*b Accelerator Pedal Sensor Assembly

PROCEDURE


  1. CHECK MIL


    1. Check that the Malfunction Indicator Lamp (MIL) lights up when the ignition switch is turned to ON.

      OK
      MIL lights up.
      Result
      Proceed to
      OK
      NG

    OK
    NG
  2. CHECK GTS


    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.

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

    B
    A
  3. CHECK MIL (THROTTLE POSITION SENSOR)


    1. Disconnect the throttle with motor body assembly connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

      Tech Tips

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

      Click here


    B
    A
  4. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)


    1. Disconnect the accelerator pedal sensor assembly connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    B
    A
  5. CHECK MIL (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. Check the MIL.

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

    B
    A
  6. CHECK MIL (CAMSHAFT POSITION SENSOR FOR INTAKE CAMSHAFT)


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

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    B
    A
  7. CHECK MIL (CAMSHAFT POSITION SENSOR FOR EXHAUST CAMSHAFT)


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

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    B
    A
  8. CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle with motor body 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
      B77-125 (VCTA) - Body ground Always 10 kΩ or higher
      A62-53 (VCPA) - Body ground Always 10 kΩ or higher
      A62-56 (VCP2) - Body ground Always 10 kΩ or higher
      B77-130 (VCIA) - Body ground Always 10 kΩ or higher
      B77-111 (VCE1) - Body ground Always 10 kΩ or higher
      B77-113 (VCV1) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK
    NG