Heat on 82° only

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Rmkuper

TYF Newbie
Joined
Oct 30, 2021
Posts
10
Reaction score
3
Just bought a 01 Yukon Denali. 100K 1 owner it's like new got a steal on it. Couple only used it to travel. Only issue I have found so far is that it will only blow hot air on the 82° highest setting or when set to auto. It will blow ambient air on any other setting. A/C blows cold. Anyone ran into this? The blower relay and door actuators seem easy to get to so I was going to start there. Any help would be appreciated. Thanks!
 

PNWYukon

Full Access Member
Joined
May 13, 2015
Posts
300
Reaction score
239
Location
Olympia, WA
Do you have any HVAC related codes?

It works fine on some settings? Seems like the blend door actuator would be controlling that.
 
OP
OP
Rmkuper

Rmkuper

TYF Newbie
Joined
Oct 30, 2021
Posts
10
Reaction score
3
That's what I'm hoping for. Although I hear there is a third actuator in my truck on the driver side and it's a PIA to get to. Hope it's not that one.
 

Colby_e32

Full Access Member
Joined
Sep 25, 2016
Posts
127
Reaction score
45
I would suspect you have an issue with the "temp" blend door actuator, which is an easy one to get to. passenger side nearest to the console. Ive had mine come unplugged a few times, and my air acted crazy! This actually happened again last week. Not sure if someone kicked it loose, or what. But i plugged it back in, working fine again. LOL
 

PNWYukon

Full Access Member
Joined
May 13, 2015
Posts
300
Reaction score
239
Location
Olympia, WA
Depending on your particular system there could be 4 actuators in your dash. As @Colby_e32 said one of the temp actuators is just right of center of the dash at the floor. If you have a full console it is a bee atch to get at. The kick cover has a bolt/screw there that is very tight to get at.

Without codes or a good reader it is a part swap, but with an 2001 they are bound to go anyway, so replacing them is a good idea. I had all of them fail in my 2005, including the recirculation actuator!
 

swathdiver

Full Access Member
Joined
May 18, 2017
Posts
19,582
Reaction score
26,269
Location
Treasure Coast, Florida
Just bought a 01 Yukon Denali. 100K 1 owner it's like new got a steal on it. Couple only used it to travel. Only issue I have found so far is that it will only blow hot air on the 82° highest setting or when set to auto. It will blow ambient air on any other setting. A/C blows cold. Anyone ran into this? The blower relay and door actuators seem easy to get to so I was going to start there. Any help would be appreciated. Thanks!
There are 4 actuators up front. The mode actuator is in the driver's footwell, the other 3 are on the passenger side. Happen to be in Florida? You need a Tech-2 to access the internal BCM codes to see what's going on.
 

foreigner

TYF Newbie
Joined
Sep 6, 2021
Posts
4
Reaction score
4
I had the same issue and my problem/solution was a defective air sensor in the cabin.

 
OP
OP
Rmkuper

Rmkuper

TYF Newbie
Joined
Oct 30, 2021
Posts
10
Reaction score
3
There are 4 actuators up front. The mode actuator is in the driver's footwell, the other 3 are on the passenger side. Happen to be in Florida? You need a Tech-2 to access the internal BCM codes to see what's going on.
No BCM codes none that HPtuners can read anyway. I Mont familiar with the ECU in this truck but I can read BCMs off my camaro with it.
 
OP
OP
Rmkuper

Rmkuper

TYF Newbie
Joined
Oct 30, 2021
Posts
10
Reaction score
3
Depending on your particular system there could be 4 actuators in your dash. As @Colby_e32 said one of the temp actuators is just right of center of the dash at the floor. If you have a full console it is a bee atch to get at. The kick cover has a bolt/screw there that is very tight to get at.

Without codes or a good reader it is a part swap, but with an 2001 they are bound to go anyway, so replacing them is a good idea. I had all of them fail in my 2005, including the recirculation actuator!
Actuators are good at least the 2 that I can get to. I just noticed tonight that when I turn the truck off I hear a noise under the glove box that sounds like the blower running at very low speed for about 10 seconds before it shuts off. Also I'm getting a noise from the rear that sounds almost like a fuel pump kicking on/off now. Does not happen all the time but started around the same time I heard the other noise in the front. I'm thinking of swaping the blower control module $90 on rock auto. Not sure what else to look at....
 

bigdog9191999

Full Access Member
Joined
Feb 3, 2020
Posts
869
Reaction score
1,018
Location
sw michigan
No BCM codes none that HPtuners can read anyway. I Mont familiar with the ECU in this truck but I can read BCMs off my camaro with it.
this is good to know, i need to read my tahoe and see if i have any codes with it. i am getting an odd acting heat. figuring blend doors, but not sure. it will work normal for about 20-30 min then blow cold/ambient air ( not a/c) but if i crank the temp to max it will go back to hot. will be grabbing my htp and taking a look as it will be easy to do.
 

Forum statistics

Threads
132,236
Posts
1,864,466
Members
96,784
Latest member
Paul C
Top