1/27/19 @ 5:35 am my truck threw this code.. "Service 4WD" after attempting to switch it from AUTO to 2HI. I was not moving, the truck was in neutral and I had just driven it the day before about 100 miles, no issues and smooth sailing. I continued to drive despite the code and the truck handled fine. Also, of course once I put it in park, the Ebrake automatically engaged.
After reading through the multiple posts on this forum, I'm less than pleased to now be a part of this. I will be making an appointment with the dealer and if they come up with any effective repairs, I will hop on here and give an update.