The U code is a "Bus Off" error. The other code is implying you have a bad O2 sensor heater circuit.


A cursory Google search reveals that Daimler indeed is using O2 sensors on the emissions system of your car.


I would replace the O2 sensor or the particulate matter sensor on bank 1 sensor 1, reset the vehicle, and see if that solves it.

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-Typos courtesy of my mobile phone.