Hello together For almost 2 months I have been driving an I40 1.7Crdi BJ 2015 EZ2016. This morning I had the problem that the MKL flashed briefly and then all the assistant systems turned yellow. Engine continues to run around without emergency run. OBDII said: DTC U0100 stands for “Lost Communication with ECM/PCM ‘A’”. It is triggered when the communication between your PCM and a particular module is interrupted. As soon as this happens, the vehicle may shut down and start as soon as possible. ise not new, unless you fix the problem that triggers the code. If you turn off the engine and restarts everything is gone. Problem then occurs again after 2-3 km. Date at hyundai at the end of August. Can I tell you what it can be? Should be on the control unit but not an expert.