ECD SYSTEM, Diagnostic DTC:U0101

DTC Code DTC Name
U0101 Lost Communication with TCM

DESCRIPTION

The ECM and transmission control ECU communicate with each other via the CAN communication line. The transmission control ECU also communicates with other computers through the ECM.

If there is a problem in this communication, the ECM sets the DTC.

U0101
DTC Detection Drive Pattern DTC Detection Condition Trouble Area
Ignition switch is ON

All of following conditions met for 1 second or more:


  • Ignition switch ON

  • +B terminal voltage 8 V or more

  • No communication between ECM and skid control ECU

    (1 trip detection logic)

  • Wire harness (CANP and CANN circuits)

  • ECM

  • Transmission control ECU assembly

WIRING DIAGRAM

A005M6IE03
*a TRANSMISSION CONTROL ECU ASSEMBLY

CAUTION / NOTICE / HINT

Go to CAN communication system for troubleshooting Click here.

Tech Tips


  • When a DTC indicating a CAN communication system malfunction is output, repair the CAN communication system before repairing each corresponding sensor.

  • Read freeze frame data using the intelligent tester. Freeze frame data records 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.

  • If the CAN communication malfunctions, there is no data output from the ECM. In this case, some of the freeze frame data is not correct and not identical to the ECM data. However the ECM data is correct.

PROCEDURE


  1. GO TO CAN COMMUNICATION SYSTEM


    1. Refer to CAN Communication System.

      Click here


    NEXT

    END