One or more heater & AC (HVAC) temperature and/or air delivery mode door actuator may fail, resulting in improper temperature or air delivery. If this occurs, fault code(s) should be stored in the HVAC control module which should assist in diagnoses.
Improper HVAC Temperature and/or Air Delivery Due to Failed Mode Door Actuator on GMC Sierra 1500
Average mileage: 104,653 (10,200–311,149)
58 people reported this problem
35 people shared problem details
A/C only cold on passenger side. Drivers side blows hot. There is no adjustment on the drivers side for temp. If you turn off the truck and then restart, it might work for a bit or not.
1999 GMC Sierra 1500164,322Visitor
When selecting where i want my air to go, it only comes through the vent at my feet and through the defrost. The dash vents do not blow any air. It seems like a common problem. Im gonna go ahead and replace the mode actuator!
1999 GMC Sierra 1500127,000Visitor
System won't deliver to air flow to the proper place, ie defrost,floor,or ac vents.
2004 GMC Sierra 1500114,000Visitor
This is a well documented problem as you can see by reading articles throughout various internet sites. For being the so called a "Professional Grade", I have had so many problems with my GMC, from the instrument cluster, steering column, bed liner, hubs, ABS, emissions, etc.... and now with the HVAC - I'd give my 2004 GMC Sierra a disappointing "F". GM needs to issue Campaign to correct this problems, since so many of their customers are experience problems due to their poor workmanship or inferior design.
2001 GMC Sierra 150075,000Visitor
Can't change heating/a/c temp unless I shut down truck and reset to desired temp and restart, then it goes to correct temp
2000 GMC Sierra 1500210,000Visitor
system won't deliver to air flow to the proper place, ie defrost,floor,or ac vents.
2001 GMC Sierra 1500151,000Visitor
Heat vent operation will only blow on the floor and windshield defrost. Does not change position when the nob is turned.
2000 GMC Sierra 1500145,000Visitor
textbook problem like all others. Temp. adjuster knob when turned to cold would only blow hot all the time. Actuator is at fault.
2003 GMC Sierra 150063,000Visitor
heat only at 90 deg.
2000 GMC Sierra 1500199,589Visitor
i have problems when i u the air or heater.i have to shut the car off for half hour before i can u the other
2004 GMC Sierra 1500113,254Visitor
a/c blows hot driver side/cold passenger side. may start cold both sides then driver side starts blowing hot and getting hotter. passenger side continues to blow cold air. tried recalibration, pulling fuses, restarting, stopping vehicle turning eng off and restarting eng and then a/c same results.
2002 GMC Sierra 1500Visitor
the air flow for both hot and cold only goes to the feet and the defrost
2004 GMC Sierra 1500120,000Visitor
Air will be blowing cold and then just start blowing hot. Switching the truck off and back on usually helps.
2014 GMC Sierra 150019,000Visitor
My ac stopped working yesterday. I've called the dealership and I'm bring it in two days from now.
1999 GMC Sierra 150068,000Visitor
heat only comes out vents
2005 GMC Sierra 150075,000Visitor
AC problem - can get into a "fault mode" (after working for 2min or 2hrs - random) where it is hot on the 2 driver vents but still cold on passenger side. Restarting fixes it every time, but no telling when will fail again, could be minutes or days. Does seem to get into this fault mode more when slowing - either braking or just let off gas, but still not reliable way to reproduce problem.
2014 GMC Sierra 150065,000Visitor
Ac blows cold on passenger side and hot on driver side this is the 3rd time I have had to caring it back unreal need a recall
2004 GMC Sierra 150061,239Visitor
Driver's side works as designed, Passenger side blows hot air? GMC dealer does not acknowledge any history of same problem. Dealer will charge $125.00+ for diagnostic and no fix, depending on the diagnostic will determine if can be fixed?
2014 GMC Sierra 150024,668Visitor
ac not working
2011 GMC Sierra 150090,500Visitor
Air blows out the vents for about 20 mins, then it starts blowing out slower and soon it is blowing out in the ducts, but not coming out anywhere, (vents, defrost or the feet ) .
I have no heat. The blower works fine. It just blows cold air. I used the air this summer....no...
its cold ,then goes cool to warm you can turn off for a few minutes and turn it back on and col...
does it go under the hood or dash, the heat is on all the time & I think it is because the actu...
A rattling noise may develop from the AC belt tensioner. This can be caused by an internal faul...
My actuator for the heat/cool selector is stuck or broke and now I get A/C on the driver side a...