Hot on 32 Cold on 31

VatamaniuckB · May 17, 2017

My truck has the digital automatic heat controls, when I have it at 32 degrees its on full blast heat, when I go to 31 degrees its full blast cold, there is no in between. I've done research for the past while on this topic and have not come up with the correct answer yet, I'm in need of some desperate help. So, I changed the air door blend actuator and no change. What is the problem? Anyone know the answer?

007matman · May 17, 2017

My truck has the digital automatic heat controls, when I have it at 32 degrees its on full blast heat, when I go to 31 degrees its full blast cold, there is no in between. I've done research for the past while on this topic and have not come up with the correct answer yet, I'm in need of some desperate help. So, I changed the air door blend actuator and no change. What is the problem? Anyone know the answer?

They get confused. My 2004 Denali had the same problem. There is a "learn" process to calibrate the door actuators so they know where they're at within the housing. I don't remember the exact process but I think it involved turning it on high (as far as it will go) turning the truck off and on waiting for 60 sec then turning it all the way down. Then turn the truck off and again on and waiting for 30 sec and then repeating the process in between.

It's a pain in the butt because it doesn't always learn the first time and multiple tries may be required.

Did you try that?

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VatamaniuckB · May 17, 2017

Yes I did try that, a few times already. Still the same problem, I will definitely look it up though. Thank you.

MaverickZ71 · May 17, 2017

My experience was that replacing a actuator or two doesn't fix it. The system air actuator doors then have to be 're-aligned' by someone using a $1200 GM scan tool in order for the Auto HVAC system to work correctly. Cost me almost $400 to have a GM dealer replace two actuators and re-align the system with their fancy Scantool.

VatamaniuckB · May 25, 2017

So, I do have the answer to my original question. I took my truck in to a Chev dealership and turns out it was not a programming issue, it was the internal cab temp sensor located in the headliner above the driver seat, the wires rubbed through. Thank you all for your help and I hope this will help anyone else out in the future.