Yukon XL Denali

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

Problem Description and Possible Solution

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.

Problem Data
RepairPal Verified
Average mileage: 130,355 (8,700–312,000)
11 model years affected: 2001, 2002, 2003, 2004, more2005, 2006, 2007, 2008, 2009, 2010, 2011
218 people reported this problem
Viewing 1 - 20 of 102 comments
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?
AC onm, blows heat on drivers side and cold everwhere else.
Cold air blows when heater is on even after 20 minutes of warming up.
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.
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!
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
A/C blows cold on driver while pass gets heat... sometimes reverses in the winter. With or without a/c.
2003 GMC Yukon Denali XL started blowing air out of defrost after a battery change. Hopefully its just a bad mode actuator.
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?
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.
I have a 2008 GMC Envoy Denali. Heater on driver side blows cold air only; passenger side works normally. What causes this problem?
Dial air isn't working. Heat on passenger side set at 90 degrees, and blowing cold air on feet and dash.
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.
Air will not come out of dash vents, Aie is coming out of defroster vents at windshield.
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.
Heat blow cold air ,and I put anti freeze in it
While on cooling mode, will switch to full heat on driver side, sometimes both sides. Not responsive to temperature adjustment.
Front blows cold while A/C is on, rear blows hot air.
After about 20 minutes running, all airflow to front dash area will be slowly diminish, eventually fully cutoff (AC, heat or outside air). This includes floor vents, dash vents and defrost. The fan runs, and all fan speeds settings work, but no air through vents.
AC cold in the back but hot up front recently, now it hot every were since adding 134A