I have a Actron cp9185 elite auto scanner. I use it on my 06 ML350 it can read and erase all check engine emission related codes and read live engine data. it cost $240.00 at autozone.,,,,,But it will not do ABS,Airbags,Airco or any secondary systems only the mercedes star or a specialized abs or airbag tool can read those codes,also I think the new snapon scanners can read and reset all that other stuff but they are about $8,000.oo
After 2003 you need some special stuff to get into the other systems the snap-on MT2500 wont work neither will carsoft 7.4.

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88 W124 3.0
96 R129 119eng
06 ML350
98 ML320 sold
02 CLK55 amg