Hi, Kj, welcome to the forum.
Unfortunately, while your English is no doubt better than my ability to translate English to your native tongue, it's quite difficult to understand your post, which in part might be why folks are not responding.
The driving test may be a reference to a driving cycle, which is part of the emissions cycles for the car that it must go through before it will report as "ready" for purposes of an emissions test, at least here in the US. I'm not sure if that is the same in other countries. If my interpretation of your translation that is the only code then enough driving cycles will clear it on it's own (and if you keep clearing it, it will never go clear).
I would guess that the Diagnosis Manual is a reference to the Factory Service Manual, which you would have to source from the dealer. It's electronic, so once loaded on a PC you'd navigate to the referenced section.
Last but not least, we do have a forum section dedicated to the A class, it is located here: W169 A-Class - Benzworld.org - Mercedes Benz Discussion Forum
That might be a place to get more useful information, too.
Good luck with it, though.