We had a heavy snow a few weeks ago and it.

We had a heavy snow a few weeks ago and it shifted into 4hi fine. Now when I try to shift back to 2hi it won't go. It has the electronic shift. When I press the 2hi button the button blinks and the transfer case makes a clicking noise as though its trying to shift but doesn't. I checked fuses and they are fine. I also checked the lube level in the transfer case and it is fine. I don't know if the lube has ever been changed. I hesitated changing the lube in fear that it may just be a waste of time if the transfer case is bad. My questions is whether or not it is the transfer case switch, transfer case control module, seals, transfer case motor, or transfer case. Any help would be greatly appreciated.