GM displays the inside temperature. That's how I knew I needed to replace the inside temperature probe, because when the climate control started acting wonky, the internal temperature always read 59 degrees. I've since gotten rid of that car, so I can't check, but I can't remember if the inside temperature toggled between set and internal, or if I had to toggle debug mode, as I know on GM cars, (or at least that one) if you press both driver and passenger temp buttons for a few seconds, it will enter diagnostic mode, and allow you to scroll thru all the sensor readings, such as engine temp, transmission temp, etc.