ECD SYSTEM (w/ EGR Cooler), Diagnostic DTC:U0101

DTC Code DTC Name
U0101 Lost Communication with TCM

DESCRIPTION

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

If there is a problem in this intercommunication, the ECM sets a 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 is 10.5 V or more

    3. No intercommunication between ECM and TCM

  • ECM

  • TCM

  • ECM to TCM circuit

WIRING DIAGRAM

A01DY9GE08

INSPECTION PROCEDURE

Note

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

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, and other data from the time the malfunction occurred.

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch ON.

    3. Turn the tester ON.

    4. Enter the following menus: Powertrain / Engine / DTC.

    5. Read the DTCs.

      Result
      Display (DTC output) Proceed to
      U0101 A
      U0101 and other DTCs B

      Tech Tips

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


    B

    GO TO DTC CHART Click here

    A

  2. INSPECT TCM


    1. A01DZZXE10

      Disconnect the T38 TCM connector.

    2. Turn the ignition switch ON.

    3. Measure the voltage of the wire harness side connector.

      Standard voltage
      Tester Connection Specified Condition
      BATT (T38-5) - Body ground 11 to 14 V
    4. A01DWWJE33

      Disconnect the T19 TCM connector.

    5. Measure the resistance of the wire harness side connector.

      Standard resistance
      Tester Connection Specified Condition
      E1 (T19-1) - Body ground Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (ECM - TCM)


    1. A01DVULE13

      Disconnect the E6 ECM connector.

    2. Disconnect the T38 TCM connector.

    3. Measure the resistance of the wire harness side connector.

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      CAN+ (E6-22) - CAN+ (T38-21) Below 1 Ω
      CAN- (E6-21) - CAN- (T38-20) Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      CAN+ (E6-22) or CAN+ (T38-21) - Body ground 10 kΩ or higher
      CAN- (E6-21) or CAN- (T38-20) - Body ground 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE ECM


    1. Replace the ECM Click here.


    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)


    1. Connect the intelligent tester to the DLC3.

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

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

    4. Read the DTCs.

      Result
      Display (DTC output) Proceed to
      No output A
      U0101 B

    B

    REPLACE TCM

    A

    END