I would get a second opinion.. Only the SUV with rear air has 2 cores..
How many people here have had an evaporator leak?
Ask to show you where it is leaking and take pictures.
P050D, rough idle on cold start.. Scan tool misfire data will show the cylinders that are misfiring.. It will only occur during a cold start.. Your not going to see anything on a test drive..
Fuel injectors are the most common failure.. Coolant leaking into a cylinder from a bad cylinder head casting is possible but not common.
Make sure GM customer care is always involved with your concerns.. The dealer is not going to do anything that GM won't pay for.. Getting payment for warranty repairs is not automatic..
The dealership is a business just like any other.. Maximizing profits and minimizing costs..
If GM won't pay for the repairs then it comes out of the dealer profits..
Always get the General involved because the General pays for the repairs not the dealer.
Did you try unhooking the neg. Cable for a couple of minutes to do a reset.? Make sure that the new battery is fully charged.. Sounds like a low voltage issue.
If you haven't seen the message on the DIC yet, it might not go into limp mode.. The DIC will state the message when it does.
You might want to post this on the HD section. This is the LD 1500 section.
Sorry about your luck man.. Any message in the DIC? Your going to have to wait and see what the dealer finds.. You really need codes for a starting point..
I have see HD trucks with light bars covering up the transmission cooler in the bumper.. This is foolish.. But this is my opinion, It might be Ok if you never tow.
I look at it this way, It's a hot summer day, A/C on, towing a trailer.
Door passthrough wiring is always a problem aria.. The wires move every time the door does.. I was going to suggest you look there, but you found it yourself.. Nice work!