The problem is that the on and the off position of the airflow plate aren't the same. It needs .7v running to enter the idle map strategy. If you are at .7v key on engine off then you will be much higher voltage when idling.
What is happening to EHA at the time all this is taking place? If it likes 0ma (disconnected) what IS happening when it don't like it?
Bosch Master, ASE Master, L1
33 years MB technician