For just rock crawling which is what I do the most just putting it in 4LO is the best option. This keeps the system on enough to grab that spinning wheel quickly and keep you moving. I've tried it with holding the button down and it didn't work to well for the rocks where you have tires off the ground all the time. For the beach I just leave it in HI and hit the button never had a problem in that configuration either. For mud and snow listen to Matt and 07jeepXK since that what they find them selves in way more then I do I avoid the stuff LOL. Also I remember reading the flow chart for the computer system and the computer is never truly off I just wish I could find that thing again.