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.

A005J3JE03

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.

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

A005IXXE04
*a THROTTLE WITH MOTOR BODY ASSEMBLY
*b ACCELERATOR PEDAL SENSOR ASSEMBLY
*c BATTERY CURRENT SENSOR ASSEMBLY

PROCEDURE


  1. CHECK MIL CONDITION


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

      OK
      MIL lights up.

    OK

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

    NG

  2. CHECK CONNECTION BETWEEN INTELLIGENT TESTER AND ECM


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Check for communication between the tester and ECM.

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

    B

    GO TO MIL CIRCUIT Click here

    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

    4. Reconnect the throttle with motor body assembly connector.

      Tech Tips

      Perform "Inspection After Repairs" after replacing the throttle with motor body assembly Click here.


    B

    REPLACE THROTTLE WITH MOTOR BODY ASSEMBLY Click here

    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

    4. Reconnect the accelerator pedal sensor assembly connector.


    B

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

    A

  5. CHECK MIL (BATTERY CURRENT SENSOR)


    1. Disconnect the battery current 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

    4. Reconnect the battery current sensor assembly connector.


    B

    REPLACE BATTERY CURRENT SENSOR ASSEMBLY Click here

    A

  6. CHECK HARNESS AND CONNECTOR (VC CIRCUIT)


    1. Disconnect the throttle with motor body assembly connector.

    2. Disconnect the accelerator pedal sensor assembly connector.

    3. Disconnect the battery current sensor assembly connector.

    4. Disconnect the ECM connectors.

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

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B23-115 (VCTA) or B29-5 (VC) - Body ground Always 10 kΩ or higher
      A58-53 (VCPA) or A36-4 (VCPA) - Body ground Always 10 kΩ or higher
      A58-56 (VCP2) or A36-1 (VCP2) - Body ground Always 10 kΩ or higher
      A58-34 (VCIB) or A31-2 (VC5) - Body ground Always 10 kΩ or higher

    6. Reconnect the throttle with motor body assembly connector.

    7. Reconnect the accelerator pedal sensor assembly connector.

    8. Reconnect the battery current sensor assembly connector.

    9. Reconnect the ECM connectors.


    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (VC CIRCUIT)