2002 GMC ENVOY outside temperature gauge incorrect - a/c issues????

Question

I have a 2002 GMC Envoy. Over the past few days, the inside temperature gauge (for the outside temp) starts out at 50 degrees (not normally the case). It will stick around 50, sometimes going up to what it really is outside (90 ).....but then reverting back to 50 when turned off. Twice now it has gone BACKWARDS to -30 degress (!!!) and during this time, the a/c will quit blowing cold air completely. Once it comes back up past 30 degrees, it will again blow cold a/c air. I wouldn't have thought these two are connected to each other - is this just a coincidence? Any thoughts are much appreciated! Thanks!

Answer 1

There is a programming update for the HVAC control module. You will need to take it to your GM dealer to have this reprogram downloaded into the vehicle. This should fix the outside air temp problem. The problem with your a/c is most likely related to your first problem. The A/C compressor is disabled in extreme cold temperatures which your vehicle is reading.