I am really not sure why MB is providing all this info for free, but some of the best training documents one could ask for are available online for free here:
http://www.mercedestechstore.com
They may be wanting the info spread so they can sell the info access CDs that are also available. Hard to imagine though as the free stuff is total professional quality stuff. Try this link, it is long and may not wrap properly, if so just paste it to your browser:
http://www.mercedestechstore.com/pdfs/507%20Systems%20I/507%20HO%20CAN%20B%20(ICC)%2010-28-02.pdf