Why does my driver ac keep going hot?

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Trey Hardy

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I can cut the Tahoe off and cut it back on and sometimes it’ll fix itself other times it don’t but it’s super annoying I’ve replaced the blend door already the one thing in the ac vent I haven’t changed yet but I got one home I may swap out this evening if all i have to do is recalibrate the system afterwards
 

YukonRog

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Could be the mixer valve (controller) or a bad vacuum hose. Since you say you can get it to do it correctly occasionally, I'd guess it's the controller. (Mixer or whatever you want to call it. LOL)
 
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Trey Hardy

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F780EE55-9343-43FD-896F-7A72E215B392.png

Blower motor resistor is what I have And never put in because I couldn’t get it to calibrate right. Think the old one is hitting the dust finally? New regulator and blower motor new door actuator
 
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Trey Hardy

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Could be the mixer valve (controller) or a bad vacuum hose. Since you say you can get it to do it correctly occasionally, I'd guess it's the controller. (Mixer or whatever you want to call it. LOL)
I do have a vacuum leak I’ve yet to find it’s been throwing the code for a while now
 

YukonRog

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What have you tried? Maybe hook up a vaccuum pump to the lines and listen? Reverse low pressure can work too. Some shops use a machine that pumps smoke. I've used a cigar and a length of tubing to check exhaust gaskets on motorcycles. Just sayin, sometimes you gotta be creative!
 

swathdiver

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I can cut the Tahoe off and cut it back on and sometimes it’ll fix itself other times it don’t but it’s super annoying I’ve replaced the blend door already the one thing in the ac vent I haven’t changed yet but I got one home I may swap out this evening if all i have to do is recalibrate the system afterwards
The driver's temperature actuator is the one in the passenger's footwell. This system does not use vacuum to control the actuators.

I've never been able to do a calibration successfully without the Tech-2.

What are your internal BCM codes?
 
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Trey Hardy

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The driver's temperature actuator is the one in the passenger's footwell. This system does not use vacuum to control the actuators.

I've never been able to do a calibration successfully without the Tech-2.

What are your internal BCM codes?
So far I have changed the blower motor the blend door actuator and the rear ac control on the console I tried to replace that blower motor resistor and couldn’t get it to calibrate right doing the fuse pull disconnect battery trick
(how I got the others calibrated)
I’m not sure if I got a bad unit or if I can only do it using the tech 2
 
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Trey Hardy

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Evap vacuum leak
And large vacuum leak
Oil pressure sensor cause I got to replace it
I got a cheapo 10$ eBay special scanner just barly enough to get the job done and to clear engine codes lol
 

swathdiver

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So far I have changed the blower motor the blend door actuator and the rear ac control on the console I tried to replace that blower motor resistor and couldn’t get it to calibrate right doing the fuse pull disconnect battery trick
(how I got the others calibrated)
I’m not sure if I got a bad unit or if I can only do it using the tech 2

Well, you need a Tech-2 or some other bi-directional scan tool that can tell you what's wrong, allow you to test the actuators, and possibly do some programming.

Only the actuators get calibrated and only the front HVAC control module gets programmed. Double check the part number of the actuator you used against the ones posted below:

1668003332701.png
 

tungsten

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So you got it fixed?

I may also have the same problem,
 
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Trey Hardy

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No it’s been doing it for awhile it’s weird it’ll start cold turn hot as hell on the driver side I cut the car off open the door start it back and it fixes instantly but eventually does it again not all the time but usually does it the one hot day of the week
 

tungsten

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No it’s been doing it for awhile it’s weird it’ll start cold turn hot as hell on the driver side I cut the car off open the door start it back and it fixes instantly but eventually does it again not all the time but usually does it the one hot day of the week
Can you see if the blender door moves?Just wondering if theres a way too visually check?
Thanks.
 

s360guitarist

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If it makes you feel, any better the passenger side blows cold when my heat is on! (2009 Yukon XL Denali)

Good luck!
 

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