You obviously didn't go where I said. The info access CDs are what they are selling but what they are giving away dewarfs them in real content.
If you follow James link it takes you to the 66 page complete CANB training document. Look at it and then go to the site:
http://www.mercedestechstore.com/ and don't change pages. Look right at the files designated 507 systems 1 and 2. Once you see how it works look at the others. This is professional technical training info on mainly brand new systems. The 507 files (whatever that means) cover cars back to about 98. There are heating and AC documents (HVAC) for MLs and 220s and 203s. There is a whole section on the 211 and 230 cars.