Improper HVAC Temperature and/or Air Delivery Due to Failed Mode Door Actuator on GMC Yukon XL Denali

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.

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Average mileage: 124,913 (8,700–312,000)
11 model years affected: 2001, 2002, 2003, 2004, more2005, 2006, 2007, 2008, 2009, 2010, 2011
118 people reported this problem
62 people shared problem details
AC onm, blows heat on drivers side and cold everwhere else.
44 people like thisFlag inappropiate
Heater blows hot on passenger side and cold on drivers side. dont get heat on defrost at dash either. What do I need to have replaced?
33 people like thisFlag inappropiate
A/C blows cold on driver while pass gets heat... sometimes reverses in the winter. With or without a/c.
24 people like thisFlag inappropiate
Front panel doesn't blow any heat or a/c. Very little heat/ac comes from the front floor vents. Only works in defrost, rear heat/ac works good.
20 people like thisFlag inappropiate
While my a/c is running, for no apparent reason the heater will kick on full blast. And just within the last few months when this occurs, at the same time, my seat heater on the driver side will mysteriously turn on High. When I realize that my seat is blazing hot & try to turn off the seat heater, it continues to turn right back on like 6-10 times in a row...every time I turn it off, within 1-2 minutes it turns right back on! This is NO Fun to deal with while I am driving in traffic or on the highway, especially when it's well over 100* outside!! Any possible explanation would be greatly appreciated! Thank you
18 people like thisFlag inappropiate
2003 GMC Yukon Denali XL started blowing air out of defrost after a battery change. Hopefully its just a bad mode actuator.
16 people like thisFlag inappropiate
While driving with the a/c on, the front driver vent will suddently blow heat. All other vents including the rear are fine and still blowing cold! I have to stop the car, turn the engine off and restart the vehilce. It will temporarily fix the problem, but it will occur again while driving!
12 people like thisFlag inappropiate
In AC or heat mode. Drivers side blows opposite of passenger and rear temp. Have had issues with climate control since purchased new on 04.
9 people like thisFlag inappropiate
Rear a/c and heat not changing to heat staying cold and not changing from ceiling to floor. Front drivers side keeps changing from hot to cool and back again without touching the controls. help, help?
6 people like thisFlag inappropiate
AC worked perfectly until this morning when it switched to blowing HIGH heat on the driver side within a few minutes after starting. Not sure about the other vents.
5 people like thisFlag inappropiate
While on cooling mode, will switch to full heat on driver side, sometimes both sides. Not responsive to temperature adjustment.
2 people like thisFlag inappropiate
Cold air blows when heater is on even after 20 minutes of warming up.
1 person likes thisFlag inappropiate
Heat and air coming out of defrost instead of front vents
Air conditioning is on but the air coming out of the vents is heated air. It does the opposite sometimes as well. I will have the heat on and the air coming out of the vents is cooled air.
my 2009 Yukon Denali Driver side ac is cooling but passenger side is blowing hot air
hot air in front.but kool air in the back?? Recharged.compressor won't run unless hot wired.
The passinger two air vents up front blow out hot air.
AC on delivers heat on driver side, cool air on passenger side. Mix door actuator suspected.
Hot on passenger side cold on driver side
ac intermittently blows heat on drivers side while still cooling the passenger side and switches between front defog, vents and floor
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