“Which Benz key programmer will add a key to this model Mercedes W210 S550?” We’ve got the technical support from a Benz owner. technicians have got two solutions 1. W210 need orange5 or xprog M ECU programmer to read. Has hc05 mcu…need to remove chip and read…then calculate and prep keys from dump. 2. Try VVDI Benz mb bga tool, w210 is in the safe zone without removing chip.