We were contacted regarding a 'typical' ISM/gear selector fault on a Benz W164 ML280, the symptom was - no crank, no start, gear selection was inhibited and the instrument cluster stated "vehicle not in position P".
Our initial diagnostic and experience with ISM faults led us to the fault being the intelligent servo module/ISM, as in the above picture.
A replacement ISM was ordered, we programmed and initialised it, the vehicle is back on the road now.