Autel ap200 / hd200 is the most affordable "generic" obd2 scanner I could find that is fully compatible for the ED. It's locked to one brand (Smart) only, not the professional version, but can read/clear codes.. You can confirm compatibility yourself if you're so inclined on the Autel web site. (all group/systems). It will read all codes and live data/etc but I haven't tried while driving.