No codes listed in the owners manual. The workshop manual has the ECU codes but no DTC codes. Those have to be pulled by the service dept. computer. 2160 rpm for 540 and 1828 for 540e.Curious as if your owners manual don't list common codes and their cause?
Kind of curious about 1800 rpm too. With my M's, rated speed (540-1000 rpm Pto is 2100 so 1800 isn't that far off and I have to presume yours having a larger engine, maybe 1800 is Pto rpm?
Do you possibly have your PTO on, set at 540e? Or just partially?
Play around with levers and switches related to the PTO.