True. We can leave it in 2WD, though, so its not always on.
The system has 2WD, 4-Auto, 4-Lock and 4-Low.
4-Auto and 4-Low do what they say, but 4-Lock acts pretty much the same as 4-Auto because of the crappy programming. If 4-Lock actually locked the truck in 4WD, it would be much better.