In most all cases it depends on what your serial number is. Not saying I have them, but they change from year to year.
Loosing comms would lead me to your boat may be drive by wire. If it is then it communicates via the CAN buss and it could be there is a loose connection or bad terminator
Code 101 and 103 are critical comms errors with the return to port message
Search for manual 90-899883333 and code listing starts at page 116
This was replaced by the one you have but Merc removed the codes. I would put a link but then the site would not let me post it