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

A01BGYIE01

INSPECTION PROCEDURE

PROCEDURE


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


    1. Connect an intelligent tester to the DLC3.

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

    3. Select the following menu items: powertrain / Engine / DTC.

    4. Read 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

    A

  2. INSPECT TRANSMISSION CONTROL ECU


    1. A01BBRJE04

      Disconnect the O3 transmission control ECU connector.

    2. Turn the ignition switch to ON.

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

      Standard voltage
      Tester Connection Specified Condition
      IG2 (O3-6) - Body ground 11 to 14 V

    4. Reconnect the transmission control ECU connector.

    5. A01BB2VE30

      Disconnect the O1 transmission control ECU connector.

    6. Check the resistance.

      Standard resistance
      Tester Connection Specified Condition
      E1 (O1-1) - Body ground 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. A01BE50E05

      Disconnect the B7 ECM connector.

    2. Disconnect the O3 transmission control ECU connector.

    3. Check the resistance.

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      CAN+ (B7-22) - CAN+ (O3-21) Below 1 Ω
      CAN- (B7-21) - CAN- (O3-20) Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      CAN+ (B7-22) or CAN+ (O3-21) - Body ground 10 kΩ or higher
      CAN- (B7-21) or CAN- (O3-20) - Body ground 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 an intelligent tester to the DLC3.

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

    3. Select the following menu items: powertrain / Engine / DTC.

    4. Read DTCs.

      Result
      Display (DTC Output) Proceed To
      No output A
      U0101 B

    B

    REPLACE TRANSMISSION CONTROL ECU

    A

    END