ECD SYSTEM (w/o DPF) VC Output Circuit

DESCRIPTION

The ECM constantly generates 5 V of power from the battery voltage supplied to the +B (BATT) terminal to operate the microprocessor. The ECM also provides this power to the sensors through the VC output circuit.

A015D95E68

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

A01559ME09
A015AAHE11

INSPECTION PROCEDURE

Note

After replacing the ECM, the new ECM needs registration Click here and initialization Click here.

PROCEDURE


  1. CHECK MIL


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

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

    A

    END

    B

  2. CHECK COMMUNICATION BETWEEN INTELLIGENT TESTER AND ECM


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON and tester on.

    3. Check the communication between the tester and ECM.

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

    A

    GO TO MIL CIRCUIT Click here

    B

  3. CHECK MIL (THROTTLE POSITION SENSOR (for Bank 1))


    1. Disconnect the C83 throttle position sensor (for Bank 1) connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    4. Reconnect the C83 throttle position sensor (for Bank 1) connector.


    A

    REPLACE DIESEL THROTTLE BODY ASSEMBLY (for Bank 1) Click here

    B

  4. CHECK MIL (THROTTLE POSITION SENSOR (for Bank 2))


    1. Disconnect the C84 throttle position sensor (for Bank 2) connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    4. Reconnect the C84 throttle position sensor (for Bank 2) connector.


    A

    REPLACE DIESEL THROTTLE BODY ASSEMBLY (for Bank 2) Click here

    B

  5. CHECK MIL (NO. 1 EGR VALVE POSITION SENSOR)

    Tech Tips

    For vehicles without EGR valve, perform troubleshooting from the next step.


    1. Disconnect the C87 No. 1 EGR valve connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    4. Reconnect the C87 No. 1 EGR valve connector.


    A

    REPLACE NO. 1 EGR VALVE ASSEMBLY Click here

    B

  6. CHECK MIL (NO. 2 EGR VALVE POSITION SENSOR)

    Tech Tips

    For vehicles without EGR valve, perform troubleshooting from the next step.


    1. Disconnect the C88 No. 2 EGR valve connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    4. Reconnect the C88 No. 2 EGR valve connector.


    A

    REPLACE NO. 2 EGR VALVE ASSEMBLY Click here

    B

  7. CHECK MIL (ACCELERATOR PEDAL POSITION SENSOR)


    1. Disconnect the A31 accelerator pedal position sensor connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    4. Reconnect the A31 accelerator pedal position sensor connector.


    A

    REPLACE ACCELERATOR PEDAL ROD ASSEMBLY Click here

    B

  8. CHECK MIL (MANIFOLD ABSOLUTE PRESSURE SENSOR)


    1. Disconnect the C80 manifold absolute pressure sensor connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    4. Reconnect the C80 manifold absolute pressure sensor connector.


    A

    REPLACE MANIFOLD ABSOLUTE PRESSURE SENSOR Click here

    B

  9. CHECK MIL (FUEL PRESSURE SENSOR)


    1. Disconnect the C82 fuel pressure sensor connector.

    2. Turn the ignition switch to ON.

    3. Check the MIL.

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

    4. Reconnect the C82 fuel pressure sensor connector.


    A

    REPLACE COMMON RAIL (for Bank 1) Click here

    B

  10. CHECK HARNESS AND CONNECTOR


    1. Disconnect the throttle position sensor (for Bank 1) connector.

    2. Disconnect the throttle position sensor (for Bank 2) connector.

    3. Disconnect the No. 1 EGR valve connector.

    4. Disconnect the No. 2 EGR valve connector.

    5. Disconnect the accelerator pedal position sensor connector.

    6. Disconnect the manifold absolute pressure sensor connector.

    7. Disconnect the fuel pressure sensor connector.

    8. A015C0EE03

      Disconnect the ECM connectors.

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

      Standard Resistance (Check for Short)
      for LHD
      Tester Connection Condition Specified Condition
      C45-90 (VCEG) - Body ground Always 10 kΩ or higher
      C45-91 (VCVL) - Body ground Always 10 kΩ or higher
      C45-70 (VCM) - Body ground Always 10 kΩ or higher
      C45-66 (VCPM) - Body ground Always 10 kΩ or higher
      A38-55 (VCPA) - Body ground Always 10 kΩ or higher
      A38-56 (VCP2) - Body ground Always 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      C46-90 (VCEG) - Body ground Always 10 kΩ or higher
      C46-91 (VCVL) - Body ground Always 10 kΩ or higher
      C46-70 (VCM) - Body ground Always 10 kΩ or higher
      C46-66 (VCPM) - Body ground Always 10 kΩ or higher
      A52-55 (VCPA) - Body ground Always 10 kΩ or higher
      A52-56 (VCP2) - Body ground Always 10 kΩ or higher

    10. Reconnect the throttle position sensor (for Bank 1) connector.

    11. Reconnect the throttle position sensor (for Bank 2) connector.

    12. Reconnect the No. 1 EGR valve connector.

    13. Reconnect the No. 2 EGR valve connector.

    14. Reconnect the accelerator pedal position sensor connector.

    15. Reconnect the manifold absolute pressure sensor connector.

    16. Reconnect the fuel pressure sensor connector.

    17. Reconnect the ECM connectors.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE ECM Click here