SFI SYSTEM, 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. Engine switch on (IG)

    2. Battery voltage is 10.5 V or more

    3. No intercommunication between engine control ECM and TCM

  • ECM

  • TCM

  • ECM to TCM circuit

WIRING DIAGRAM

A01GL9TE01

INSPECTION PROCEDURE

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG).

    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. A01GK3QE05

      Disconnect the A12 TCM connector.

    2. Turn the engine switch on (IG).

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

      Standard voltage
      Tester Connection Switch Condition Specified Condition
      A12-6 (+B) - Body ground Engine switch on (IG) 11 to 14 V

    4. Disconnect the E5 TCM connector.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      E5-7 (E1) - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      OK A
      NG (for 2WD) B
      NG (for AWD) C

    B

    GO TO TCM POWER SOURCE CIRCUIT Click here

    C

    GO TO TCM POWER SOURCE CIRCUIT Click here

    A

  3. CHECK HARNESS AND CONNECTOR (ECM - TCM)


    1. A01GNJZE05

      Disconnect the A13 ECM connector.

    2. Disconnect the A12 TCM connector.

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

      Standard resistance (Check for open)
      Tester Connection Condition Specified Condition
      A13-9 (CAN-) - A12-28 (CAN-) Always Below 1 Ω
      A13-10 (CAN+) - A12-18 (CAN+) Always Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Condition Specified Condition
      A13-9 (CAN-) or A12-28 (CAN-) - Body ground Always 10 kΩ or higher
      A13-10 (CAN+) - A12-18 (CAN+) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE ECM


    1. Replace ECM Click here.


    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the engine switch on (IG) 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
      Result
      Result Proceed to
      OK A
      NG (for 2WD) B
      NG (for AWD) C

    B

    REPLACE TCM Click here

    C

    REPLACE TCM Click here

    A

    END