2008 Chevy Tahoe temp reading in rear view mirror wildly

inaccurate. Suspect sensor

 

I think I recently read something about it in my owners manual on my 2004 Tahoe. It has the same feature. Can't remember exactly but it may tell you how to recalibrate it, if you have your owners manual.

 

the reading isnt live so until it updates, it won't be accurate. you can update the sensor reading but you can't recalibrate it. if its wrong all the time...ohm check the signal and return wires to the sensor.