SFI SYSTEM VC Output Circuit

DESCRIPTION

The ECM constantly generates 5 V power from the battery voltages supplied to the +B terminal and +B2 terminal to operate the microprocessor. The ECM also provides this power to the sensors through the VC output circuit.

A004IXRE05

When the VC circuit is short-circuited, the sensors that are supplied with power through the VC circuit are deactivated because the power is not supplied from the VC circuit.

WIRING DIAGRAM


A004I5CE02
A004J97E02

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK CONNECTION 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 for communication between the GTS and ECM.

      Tech Tips

      Checking the Data List for "Engine" is possible.

      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 (ECM)


    1. Turn the ignition switch to ON.

    2. A004IC1E02

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A34-6 (+B) - A36-4 (E01) Ignition switch ON 11 to 14 V
      A33-1 (+B2) - A36-4 (E01) Ignition switch ON 11 to 14 V

      Tech Tips

      If the result is not as specified, the system may not be activated due to no power supply to the ECM terminals +B and +B2.


    NG

    CHECK ECM POWER SOURCE CIRCUIT Click here

    OK

  3. CHECK SHORT CIRCUIT (THROTTLE POSITION SENSOR)


    1. Disconnect the throttle with motor body assembly connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      Checking the Data List for "Engine" is possible.

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

    B

    REPLACE THROTTLE WITH MOTOR BODY ASSEMBLY Click here

    A

  4. CHECK SHORT CIRCUIT (MANIFOLD ABSOLUTE PRESSURE SENSOR)


    1. Disconnect the manifold absolute 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

      Checking the Data List for "Engine" is possible.

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

    B

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    A

  5. CHECK SHORT CIRCUIT (FUEL PRESSURE SENSOR)


    1. Disconnect the fuel 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

      Checking the Data List for "Engine" is possible.

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

    B

    REPLACE FUEL PRESSURE SENSOR Click here

    A

  6. CHECK SHORT CIRCUIT (CRANKSHAFT POSITION SENSOR))


    1. Disconnect the crankshaft 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

      Checking the Data List for "Engine" is possible.

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

    B

    REPLACE CRANKSHAFT POSITION SENSOR Click here

    A

  7. CHECK SHORT CIRCUIT (ACCELERATOR PEDAL SENSOR ASSEMBLY)


    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 the GTS and ECM.

      Tech Tips

      Checking the Data List for "Engine" is possible.

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

    B

    REPLACE ACCELERATOR PEDAL SENSOR ASSEMBLY Click here

    A

  8. CHECK SHORT CIRCUIT (BATTERY CURRENT SENSOR ASSEMBLY)


    1. Disconnect the battery current sensor assembly connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      Checking the Data List for "Engine" is possible.

      Result
      Result Proceed to
      Communication is not possible (w/ EVAP System) A
      Communication is not possible (w/o EVAP System) B
      Communication is possible C

    B

    CHECK HARNESS AND CONNECTOR (EACH SENSOR - ECM) Click here

    C

    REPLACE BATTERY CURRENT SENSOR ASSEMBLY Click here

    A

  9. CHECK SHORT CIRCUIT (CANISTER PUMP MODULE)


    1. Disconnect the canister pump module connector.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Check the communication between the GTS and ECM.

      Tech Tips

      Checking the Data List for "Engine" is possible.

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

    B

    REPLACE CANISTER PUMP MODULE Click here

    A

  10. CHECK HARNESS AND CONNECTOR (EACH SENSOR - ECM)


    1. Disconnect the throttle with motor body assembly connector.

    2. Disconnect the manifold absolute pressure sensor connector.

    3. Disconnect the fuel pressure sensor connector.

    4. Disconnect the crankshaft position sensor connector.

    5. Disconnect the accelerator pedal sensor assembly connector.

    6. Disconnect the battery current sensor assembly connector.

    7. Disconnect the canister pump module connector.*

      *: w/ EVAP System

    8. Disconnect the ECM connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A36-19 (VC) - Body ground Always 10 kΩ or higher
      A35-22 (VCP2) - Body ground Always 10 kΩ or higher
      A35-21 (VCPA) - Body ground Always 10 kΩ or higher

    OK

    REPLACE ECM Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR