OBD2 scaner

There are so many types of generic ones that only read out the regular ODB II codes.
They range from $40 to $200.
If you are looking for one that can do the MB specific codes there are also a variety of those. They are all over the place in price depending on features.

Do you have a particular one in mind?

Well then I agree with the others that the 3100 is really a good unit at a good price.

They will still communicate and report things like no codes, some real time data while
the engine is running and other things depending on the unit.

That is why they are at a retail chain store for $8 an hour. I actually have the same Actron
tool most of the Auto Zones use and it does a lot more than just pull codes.
I also have a MB Star SDS so for the hairy stuff I break out the computer and run the
MB DAS software.

I think you will be pleased.