HVAC Actuator Recalibration Procedure For GM Trucks and SUVs

The topic of how to perform the actuator recalibration procedure on Chevrolet , GMC and Cadillac Trucks and SUVs has become an ever increasing topic of discussion.

For manual systems it does not matter where the a/c controls are set but if you feel the need to do something, turn the blower switch on (I prefer speed 3) and set the temperature sliders about .5″ to .75″ from full cold.

For auto systems, press the auto button, with the key on.

Turn the ignition off.

Remove the HVAC/ECAS , 10 amp fuse in the underhood fuse box* or disconnect the battery for one minute.

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*Fuse locations can vary from year to year and between different models. Hopefully I will be able to build a list for this.

Install the HVAC fuse or reconnect the battery.

Start the engine. On systems with auto a/c controls the controls will default to 74 degrees F when the ignition is turned back on.

DO NOT TOUCH the a/c controls.

Let the engine run for 1-2 minutes.
Turn the ignition off for at least 10 seconds but no more than 30 seconds.
Restart the engine and then test the a/c controls.

301 discussions on “HVAC Actuator Recalibration Procedure For GM Trucks and SUVs”

  1. Ok so I have a 2011 GNC Sierra Denali. I know this is an electrical problem because it started after my battery died. I pulled the cable and it worked…. last night… this morning woke up to drive my truck blowing hot air everywhere followed the reset tips above and still blowing hot on both sides. Any ideas?

    1. Assuming that you have properly performed the recalibration I would have to think that there is a faulty actuator or two. Slight chance that there could be a poor battery cable connection. If you want to discuss further please use the “Ask a Question” section.

      To use the “Ask a Question” section of this site to finish the conversation. Locate the “My Account” or “Login” button at the top right of the page if on a desktop or laptop. Within the menu symbol if using a phone. After you are logged in to your account click on the “My Account” button and scroll down until you see the “My Questions” section. Copy and paste your last comment into it as if you were replying and then I will do the same. I want to keep the full discussion in one location so it can help others. Thanks, Sparky

  2. So Sparky on my 07 Burb Z71 with Auto Climate Control, it is blowing liquid magma temp hot air out driver side but cool out Passenger. I tried your provided recal process as well as almost every other “Alt” version without a Tech2 minus the door open/close method. I have replaced 3 of 4 actuators (drivers, behind glove box, & bottom middle right above the drivetrain floor “bump”). Only one I haven’t replaced is the top middle behind the center vents but I don’t think it’s an actuator any longer as it seems the buzzing is gone now that originally led me to replace the actuators. I haven’t noticed any dimming of the Climate Control Module but outside of replacing that I’m drawing a blank as to how to get it calibrated without having take it to a dealership cus I prefer to use my own hands lol. Any advice or guidance will be welcomed

  3. I have been battling hot flashes in my 04 Yukon Denali for a few years, have used this reset a few times but I think the actuators ate toast this year. Where might I find the actuators? I believe both driver and passenger need replaced, both sides blow opposite of what they should, driver side is worse. A step by step to replacement would be wonderful!
    Thank you for saving this Sparky DIYer her next few paychecks!

    1. The following links all apply to your vehicle. If you have any more questions please use the Ask a Question section. You will need to open your account by clicking on the “My Account” button. Scroll down the page and click on the “Open a Ticket” link that is highlighted in green.

      2004 Chevrolet Tahoe Blows Hot Air

      2005 Cadillac Escalade, Driver’s Side Vents Blow Hot Air, A/C On

      2006 Chevrolet Silverado-Driver’s Temperature Door Erratic

      2003 Chevrolet Silverado, HVAC Actuator Stuck

      2004 Chevrolet Silverado, Dash Cover Removal

      2004 Chevrolet Silverado, Changing The Passenger Side Blend Door Actuator, B0424

      1. So Sparky on my 07 Burb Z71 with Auto Climate Control, it is blowing liquid magma temp hot air out driver side but cool out Passenger. I tried your provided recal process as well as almost every other “Alt” version without a Tech2 minus the door open/close method. I have replaced 3 of 4 actuators (drivers, behind glove box, & bottom middle right above the drivetrain floor “bump”). Only one I haven’t replaced is the top middle behind the center vents but I don’t think it’s an actuator any longer as it seems the buzzing is gone now that originally led me to replace the actuators. I haven’t noticed any dimming of the Climate Control Module but outside of replacing that I’m drawing a blank as to how to get it calibrated without having take it to a dealership cus I prefer to use my own hands lol. Any advice or guidance will be welcomed

  4. I have a 2011 SRX Performance Edition. I have tested and isolated my issue to a probably actuator calibration issue. Both passenger and driver actuators are working although when on cool, the driver side either starts off cool and slowly moves to just fan (warmer) or simply is never cool while the passenger side remains cool. MOST of the time the passenger side works as intended but, at times, does the same. I deduced it was a calibration issue because the idea that both actuators were slowly going bad simultaneously would be both ironic and rare. I followed this procedure above although had many differences. My HVAC fuse is in the instrument panel box location on the passenger side floor panel. After ensuring the dual zone control was linked and on auto and turning the car off, I removed the fuse for 2 or so minutes. When I replaced the fuse, I immediately heard the actuators inside the dash moving and waited for the sounds to cease (around 45 seconds). I then started the car and the system was not on 74 nor did it seem to cycle through any reset. I still waited the 1 minute or so and then stopped the car for 15 seconds and restarted. What is different about the 2011 srx and can I do a manual reset/calibration at all?

    1. Looking at the diagram the fuse you need to pull should be labeled 47 or F26DA. After reinstalling it just start the engine and allow it to run for a minute or two. Then finish the recalibration as you did the last time. I should point out that the symptom you described fits more with a low refrigerant charge than an actuator problem.

      1. 05 tahoe, Question, I replaced the actuator, when i turned the vehicle back on, it only blew out the defrost hvac, didnt have this issue before the change, just had hot air blowing on drivers side. Not sure if i need to recalibrate again? Or is it a separate issue? Thanks!

        1. I am guessing that you changed the driver’s temperature door actuator that is located under the passenger side of the dash just above the transmission hump in the floor pan. If so, you probably have one of two things going on with the lack of vent control. Either the recalibration was not successful due to an improper process or it could not complete due to a faulty actuator. There is also the chance that it can not complete the recalibration due to the wrong part number actuator being installed. What is the part number of the actuator that you replaced? Where was it located? Does your Tahoe have manual or auto controls?

      2. Thanks for the advice. I actually had the vehicle checked for leaks and then recharged totally right before starting down this pat. If its low again, then my 20 year+ mechanic missed a leak and he’s never missed on anything before. Just this week it began blowing very cool on both sides and stayed that way on my first drive of the day. Later in the day it would start cool on both sides and then slowly move to much less cool (yet never hot or as outside air) on the drivers side while remaining cool on the passenger side. When this begins to happen, I turn off the system while on auto, wait about 10 seconds, and turn it on again. It returns to very cool and then slowly begins the warming again as described above. Any more ideas that may help? Is there an easy and inexpensive way for me to check the charge and recharge myself to see if it makes a difference?

        1. I may be able to help but need you to use the “Ask a Question” section of this site. Locate the “My Account” or “Login” button at the top right of the page if on a desktop or laptop. Within the menu symbol of using a phone. After you are logged in to your account click on the “My Account” button and scroll down until you see the green “Open a Ticket” link. Click on it and ask your questions there. Thanks, Sparky

  5. Hey Sparky, I seem to have an odd problem that I can’t find even a remotely close solution to on the web. Everything about my A/C works fine except for when I want it off. With the fan setting on 0 it still blows air at a little less than level 1 speed, so I can never get the fan to truly ever stop completely. It’s a 2004 Chevy duramax with manual control

    1. I suspect the issue is only there while the vehicle is moving down the road and it is completely normal. It is ram air coming through the fresh air door. You can mostly eliminate it by switching the fresh air door to recirculate.

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