2024 GMC Denali Ultimate: Outside Temperature Sensor Erratic

[Shawn T]

We recently went on a camping trip and I noticed that the climate control was acting finicky.  It was 80 degrees F when I got to start my truck to take a drive.  The auto-cooled seats did not come on nor did the climate control act like it wanted to cool the cabin down very rapidly.  I looked at the ambient outside temperature on the dash and it was 53 degrees F.  I drove the truck for several minutes and the temperature did not recalibrate, it stayed at 53 for the remainder of the day.  That afternoon, I decided to disconnect the batteries for about 10 minutes and do a hard "reboot".  I started the truck back up and the temperature read 91 degrees F, almost a 40-degree delta.  Well, I just figured it was a lot closer to the actual ambient of 80 degrees and turned the truck off for the day.  The next morning I checked the ambient temperature (thermometer and phone app) and it was 64 degrees F.  When I started the truck up, the temperature was at 91 degrees again.  We hooked up the 5th wheel and traveled home, going over passes and on the I-25 corridor when morning temperatures were constantly in flux, and the truck thermometer dropped to 86 degrees F at one point when the actual ambient was just above 70 degrees.  When we got home it had climbed back to 91 degrees again and stayed, only about 5 degrees high for the ambient at midday.  I see a few posts on this topic in the forum where the truck is taken into the dealership and they throw parts at it, mainly the outside temperature sensor.  I have owned dozens of GM vehicles with ambient temperature sensors since the late 90s and never experienced a bad one, although they may be a little inaccurate, nothing like this.  Are there any other issues that could be causing this before I take it in?