Strange thing happened yesterday on way home from work. I run my climate control system on manual all the time and adjust heat myself and when my wife is in truck she adjusts heat for her side otherwise they are linked with one control. Well yesterday even with control set at 90 degrees it was blowing cold outside air. I tried to adjust from 75 to 90 with no change and also shut system off and on. I then switched to passenger mode and that side blew hot air but drivers side still blew cold air with both set at 90 degrees. I then took drivers side control and lowered to lowest setting (60 degrees) and then put it back to 90 and then it started working again. Has anyone ever had that happen or have an idea what went wrong. Maybe a duct or valve sticking. Truck has 15,000 miles on it with no problems till this. This was the first time this ever happened. Thanks for any imput and Happy New Year to all.

Happened to me on my 03. Thats how I cleared it - the way you did. I just never go to the max heat setting in manual after that.

Happened once with mine where it wouldn't adjust the temperature right or adjust where it was blowing out of. I think it was around 20,000 miles when it happened. Turned the truck off, turned it back on and it has been fine ever since (I'm at 38,000 miles now).

My guess that the computer got confused, but I would write a note and throw it in the glove box with date time and miles problem and how it was solved to see if there is a trend to get the dealer to fix in the future. Was it cold ... maybe the controller got cold so to speak just a W.A.G.

Computer confused. I miss the days that a cable controlled it and it broke. LOL Thanks guys for your input and any more is great. So far all is working as GM planned. Just want to stay warm in a $50,000 dollar truck. What a joke. This message is computer generated $$^(^))^))^&%$#@#$%^&*(. Oh know REBOOT. 2009

Mine had problems three or four times last year. I would shut truck down for three or four minutes and then it was fine. This year it was happening about three or four times a week so I took it in and they flashed the computer and now it works fine.

Mine had problems three or four times last year. I would shut truck down for three or four minutes and then it was fine. This year it was happening about three or four times a week so I took it in and they flashed the computer and now it works fine.

Thanks for the information. If it starts happening again I'll make an appointment with the dealer. Had a feeling it was computer generated.

This forum sure is great for sharing information and getting answers from users, thanks again.