I would replace it as the other is probably not far behind. The compressor does not usually go out but the constant running will eventually wear it out. Maybe do a Google search on the compressor running and something should pull up on this forum and the other truck forum as this has been discussed. Good luck.
Do a Google search and it should pop up. The Corvette forum and the other Truck forum both had a list of GM Dealers who offered a great price. Good luck with your search.
These threads always seem to be counterproductive. What is the best oil,gas,spark plugs ect.,ect.,ect. I don't understand how you would not be more confused after reading everyone's opinion and whose opinion out of the many do you go with. These are on all forums. Just use a good quality product and stick with it which is what most of us do.
Have you tried a Google search, just enter "2015 Denali stuck in 4hi", if its been discussed it should pull up including all truck forums, TSBs, Recalls, ect. Good luck.
I know it cost more but I have had good luck with the Range Autostop eliminator with no issues with over a years use. I didn't want to pull all the trim off. The Range is just a plug and play unit.
Kickrocks, I would be setting up a meeting with the Service Manager to discuss your options letting him/her know that you just spent $600 to fix the problem and it is still there. I would be professional but stern on them taking another look at the issue on their dime. He has the authority to do so. Also ask him about being told to throw your other remote away. Good luck.