I wasn't as lucky as I thought. Next day no more 4WD. I tried various ways to replicate what I may have done to get it working that one day, and here is what I found. If I jack up the front tires one at a time and rotate the wheels back a forth until they stop, then I get 4Wd for a while. I'm at a total loss now. Could that be a sensor that isn't registering or stops registering because it is so friggen cold outside, until I rotate the wheels a bit? This is sooooooo frustrating. Especially when I just got to experience how awesome this vehicle is when working properly and then lost it again the next day.