2020

Didnt read about the 15 second thing until now, but yesterday I had the dealer Update or reflash my truck with the UF3 Fast Idle Feature (my 3500 didnt come with it) Was about $150 to "rewrite" the computer from GM. I tested it and it ran for over 3 hours without shutting down. Remote left inside the cab (just like if it had a key, it would need to be inside) You can test if you already have the fast idle feature in your truck by start truck, parking brake on turn cruise control on press "set" (make sure youre not pressing on the brake) If your idle goes up, then you have it, if it doesnt you dont. to disengage the fast idle press on the brake or turn off cruise control, to engage it again just "set" your cruise again without pressing on the brake. hope this helps, it definitely worked for me yesterday tested it for almost 3.5 hours. Not sure how long itll stay on but at least I can sleep at cold rest stops longer than one hour now.

Was the remote inside the truck while you were testing it?

Were you able to ever figure this out?

Any updates to this? anyone figure out a way to keep it running yet?