So getting into diagnostic menu is the same (three quick presses of start), but getting into the hidden menu involves holding the "list" button for about 20 seconds.
Once in there, though, I couldn't figure out how to activate anything. I was able to go into the other menu items by long pressing the "list" button, but couldn't activate things. I tried all the other buttons and they simply did their normal functions.
So, while I see the "service brake" option in the photos below, I couldn't figure out how to activate it. I'll do more searching to see if I can figure it out.
