ECD SYSTEM (w/o DPF), Diagnostic DTC:U0101

DTC Code DTC Name
U0101 Lost Communication with TCM

DESCRIPTION

The ECM intercommunicates with the transmission control ECU through the Controller Area Network (CAN).

If there is a problem in this intercommunication, the ECM sets the DTC.

DTC No. DTC Detection Condition Trouble Area
U0101

  • Following conditions are met for 1.25 seconds (1 trip detection logic):


    1. Ignition switch ON

    2. Battery voltage 10.5 V or more

    3. No intercommunication between ECM and transmission control ECU

  • ECM

  • Transmission control ECU

  • ECM to transmission control ECU circuit

WIRING DIAGRAM

A01BDI1E01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC U0101)


    1. Connect the intelligent tester to the DLC3.

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

    3. Enter the following menus: Powertrain / Engine and ECT / DTC.

    4. Read the DTCs.

      Result
      Result Proceed to
      U0101 is output A
      U0101 and other DTCs are output B

      Tech Tips

      If any DTCs other than U0101 are output, troubleshoot those DTCs first.


    B

    GO TO DTC CHART

    A

  2. INSPECT TRANSMISSION CONTROL ECU


    1. A01BBRJE09
      Text in Illustration
      *1 Transmission Control ECU

      Disconnect the O3 transmission control ECU connector.

    2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      O3-6 (IG2) - Body ground Ignition switch ON 11 to 14 V

    4. Reconnect the transmission control ECU connector.

    5. Disconnect the O1 transmission control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      O1-1 (E1) - Body ground Always Below 1 Ω

    7. Reconnect the transmission control ECU connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (TRANSMISSION CONTROL ECU - ECM)


    1. Disconnect the D71 ECM connector.

    2. Disconnect the O3 transmission control ECU connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      D71-24 (CAN+) - O3-21 (CAN+) Always Below 1 Ω
      D71-18 (CAN-) - O3-20 (CAN-) Always Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      D71-24 (CAN+) or O3-21 (CAN+) - Body ground Always 10 kΩ or higher
      D71-18 (CAN-) or O3-20 (CAN-) - Body ground Always 10 kΩ or higher

    4. Reconnect the transmission control ECU connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE ECM


    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)


    1. Connect the intelligent tester to the DLC3.

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

    3. Enter the following menus: Powertrain / Engine and ECT / DTC.

    4. Read the DTCs.

      Result
      Result Proceed to
      No DTC is output A
      U0101 is output B

    B

    REPLACE TRANSMISSION CONTROL ECU

    A

    END