SFI SYSTEM (w/ Electronic Throttle Control System), 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 illuminates the MIL and sets a DTC.

DTC No. DTC Detection Condition Trouble Area
U0101

  • Following conditions are met for 0.7 seconds or more (1 trip detection logic):


    1. Ignition switch ON

    2. Battery voltage 10.8 V or more

    3. No intercommunication between ECM and transmission control ECU

  • ECM

  • Transmission control ECU

  • Open or short in ECM and transmission control ECU circuit

WIRING DIAGRAM

A01366PE01

INSPECTION PROCEDURE

Tech Tips

If the CAN communication malfunctions, the transmission control ECU cannot receive the current data from the ECM. In this case, the freeze frame data output from the transmission control ECU has not been updated so it will not be useful information for the inspection procedure. However, reading the Data List as the first step of troubleshooting is effective for finding malfunctions.

Note

After replace the ECM, perform electronic throttle learning Click here

PROCEDURE


  1. CHECK OTHER DTC 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. Select the following menu items: Powertrain / Engine and ECT / 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

    A0137EOE01

    1. Disconnect the Transmission Control ECU (TCM) connector.

    2. Turn the ignition switch to ON.

    3. Measure the voltage.

      Standard voltage
      Tester Connection Specified Condition
      +B (A27-1) - Body ground 9 to 14 V

    4. Measure the resistance.

      Standard resistance
      Tester Connection Specified Condition
      GND (A27-6) - Body ground Below 1 Ω

    5. Reconnect the transmission control ECU connector.


    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR (BATTERY - TCM, TCM - BODY GROUND)

    OK

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

    A0137HKE01

    1. Disconnect the ECM connector.

    2. Disconnect the transmission control ECU connector.

    3. Measure the resistance.

      Standard resistance (Check for open)
      Tester Connection Specified Condition
      CAN+ (B25-64) - CAN+ (A28-1) Below 1 Ω
      CAN- (B25-45) - CAN- (A28-2) Below 1 Ω
      Standard resistance (Check for short)
      Tester Connection Specified Condition
      CAN+ (B25-64) or CAN+ (A28-1) - Body ground 10 kΩ or higher
      CAN- (B25-45) or CAN- (A28-2) - Body ground 10 kΩ or higher

    4. Reconnect the transmission control ECU connector.

    5. Reconnect the ECM connector.


    NG

    REPAIR OR REPLACE HARNESS AND CONNECTOR

    OK

  4. REPLACE ECM


    1. Replace ECM Click here.

      Note

      After replace the ECM, perform electronic throttle learning Click here.


    NEXT

  5. CHECK WHETHER DTC OUTPUT RECURS (DTC U0101)


    1. Connect the intelligent tester to the DLT3.

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

    3. Select the following menu items: Powertrain / Engine and ECT / DTC.

    4. Read DTCs.

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

    B

    REPLACE TRANSMISSION CONTROL ECU

    A

    END