СИСТЕМА ECD, Diagnostic DTC:U0101

DTC Code DTC Name
U0101 Lost Communication with TCM

DESCRIPTION

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

If there is a problem with this communication, the ECM stores a DTC.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Memory
U0101 Lost Communication with TCM

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


  • The battery voltage is 10.5 V or higher.

  • No communication between the ECM and TCM.

  • ECM

  • TCM

  • ECM to TCM circuit

 Comes on DTC stored

CONFIRMATION DRIVING PATTERN

U0101
DTC Detection Drive Pattern Ignition switch to ON for 3 seconds

WIRING DIAGRAM

A01LG7JE17
*a ECU-B NO. 3
*b FL MAIN 3.0W
*c Battery

PROCEDURE


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


    1. Connect the GTS to the DLC3.

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

    3. Enter the following menus: Powertrain / Engine / Trouble Codes.


      Powertrain > Engine > Trouble Codes

    4. Read the DTCs.

      Result
      Result Proceed to
      DTC U0101 is output A
      DTC 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 Click here

    A

  2. INSPECT TCM POWER SOURCE CIRCUIT (POWER SOURCE AND BODY GROUND)


    1. A01L8GEC27
      *a

      Rear view of wire harness connector

      (to TCM)

      Disconnect the TCM connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G90-5 (BATT) - C77-1 (E1) Ignition switch ON 11 to 14 V

    3. Reconnect the TCM connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (ECM - TCM)


    1. Disconnect the TCM connector.

    2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G83-22 (CAN+) - G90-21 (CAN+) Always Below 1 Ω
      G83-21 (CAN-) - G90-20 (CAN-) Always Below 1 Ω
      G83-22 (CAN+) or G90-21 (CAN+) - Body ground or other terminals Always 1 MΩ or higher
      G83-21 (CAN-) or G90-20 (CAN-) - Body ground or other terminals Always 1 MΩ or higher

    4. Reconnect the TCM connector.

    5. Reconnect the ECM connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE ECM


    1. Replace the ECM.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)


    1. Connect the GTS to the DLC3.

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

    3. Enter the following menus: Powertrain / Engine / Trouble Codes.


      Powertrain > Engine > Trouble Codes

    4. Read the DTCs.

      Result
      Result Proceed to
      DTC is not output A
      DTC U0101 is output B

    A

    END

    B

    REPLACE TCM Click here