Thanks for the time you took to put these thoughts down. There is no check engine light on at all. The dealer is telling me they can't find any codes. I know everyone is saying it won't lockout due to temp, yet it's off the first time this ever happened was the first day it dropped below 50, and it happens every morning on my commute when temps are below 50, and never happens in the afternoon when above. And with all due respect, I've been driving trucks. including this one, for many years, so there is no user error. I'm not inadvertently hitting the +/- button in any way when I'm beginning my day. In the video, I am pounding the + button to fight the truck because it is locking them out on its own, even when I'm nowhere near the buttons. And to your question, if I don't fight it with the + then it locks out all the way down in first and I can't get out of first, at all. It resets and unlocks all gears whenever I go into and out of neutral, or go in and out of manual shift mode, but then immediately begins locking out again. I know it's a weird one to try to figure out, I was posting in the hope that MAYBE someone else has had their truck do something similar.

 

Has the dealership or yourself checked the fluid level? it is doable yourself if you let the trans get to operating temp, crawl under the truck and pull the little plastic dipstick/plug on the driver's side of the trans

 

They say they did, but I may check again. Thanks for the suggestion.