Hopefully someone on here has seen this issue before and can enlighten me. The other day I parked my truck off-road to do some hiking and climbing. It was in 2wd. When I got back and tried to drive out I found I was stuck. Thinking this wasn't a problem since it's 4wd I shifted it from 2wd to 4hi. I heard the distinct whirring sound and the light under the 4hi flashed with the light under the 2wd staying solid. After a few seconds the service 4wd light came on. I shifted it back to 2wd and after a short whirring sound the flashing light under the 4hi stopped flashing and went out. The service 4wd light was still on. I turned the truck off then back on and the service 4wd light stayed off. I shifted to neutral and tried to go into 4lo with the exact same symptom. I tried this several times with no luck getting it in any 4wd selection. Luckily I was able to get it unstuck and out in 2wd. I got back to my camper and played with it a bit. It did eventually shift into 4wd and now seems to work but every once in a while is giving me the same symptom (I've been testing it for the last couple days). Any ideas of what the problem may be? I don't want to end up with an expensive repair in the end.