Check Engine Code: P0073 https://www.obd-codes.com/p0073
Purchase a cheap 10K thermistor. The one in the photo cost $0.21/each. Mine is a larger tolerance and higher Beta range, but it is working for my Jeep. This a dumb simple little sensor that should not cost much to replace or be a lot of work. I've read main other forums of people going to dealers and having many issues. Vehicles should not be hard to fix. People should also learn how to be independent of the dealer and fix their own issues.
Remove the cap on the mirror housing, you do not have to remove the mirror from the door. Cut off the OEM sensor wires as soon. The photo shows the sensor out of the mirror housing. This is so I could look at it as I explored options. I did place it back in the housing so that the mirror appeared OEM from the outside and keep the hole in the housing blocked as OEM. If you are doing this, just cut the wires
Attach the thermistor to striped wires where the out sensor was cut off. I did test the thermistor before soldering to make sure it worked. My Jeep is currently reading 2-3 degrees F from surrounding thermometers and weather apps. I would suggest testing the thermistor you get like this to make sure it works for you. Make sure to slip on the heat shrink before soldering.
Step 4: Finish the heat shrinking so that the wires can not touch. I added a larger heat shrink tube over both wires and wrapped it in electrical tape. Ziptied the new sensor to the wiring loom to keep high and dry. This appears to be the cleanest place inside the mirror housing.
Step 5: Clear the engine check code.
This is just my findings and modifications I did. It is up to you figure out what is best to do for your issue. I choice to replace the part with a $0.21 part instead of purchasing a $336 mirror assemble from Jeep. That is what I was quoted at the dealer before labor. Still waiting to hear back about this being covered under warranty, I'm not holding my breath.
Now I have no check engine light and I can use my A/C. Now I have mentioned that 4WD function can be lost and I've seen that in pre 2015 Renegade (which is the older models) videos for P0073 issues. It has not been verified in mine, but I think it is something to watch out for.