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DTC U0101 Lost Communication with TCM: Description

The engine control unit and the transmission control unit are located inside the ECM. The engine control unit intercommunicates with the transmission control ECU through the Controller Area Network (CAN). If there is a problem in this intercommunication, the ECM sets a DTC.

DTC DETECTION CONDITION AND TROUBLE AREA

DTC No. DTC Detection Condition Trouble Area
U0101 Following conditions are met for 2 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 ECU and transmission control ECU
ECM