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. I have a 2006 yukon xl with 1003,000 miles and auto climate control. System seems to do what ever it wants, meaning temp will change from cold to hot or hot to cold randomly and it seems to be mostly on the drivers side, but also happens on passenger side. Also you can not get much air from the floor vents, it always blends with the dash vents or defrost, and I find it hard to believe that all of these actuators could have gone bad at one time. I have tried recalibration as you specified both by fuse removal and battery disconnect, it will work for a couple of days and then problems start again. Now the air conditioner will not work either, and up until now it worked just fine. The system has been on a scan tool and it showed the called for position of blend doors and actual position varied greatly, but it also showed no trouble codes. Is there any chance the climate control module could have gone bad, and if so, is there a way to test it. Any info would be greatly appreciated.

  2. Hi Tony,

    It sounds like the refrigerant level is low. Without gauges the best place to check temperatures is where the lines are attached to the evaporator core near the fire wall. The small line going into the evaporator and the large line coming out and going to the accumulator tank should be nearly equal in temperature and they should be cold with the a/c on and stabilized. Be careful of do it yourself kits that have oil and sealer mixed in. They can cause larger problems.

  3. I have a 2004 Cadillac Escalade and I’m getting cool air but not cold, I’ve tried the manual reset remove the hvac fuse the disconnect battery and followed the step procedure that Sparky posted, however I’m not getting cold air.
    I just replaced the clutch for the cooling fan, blows a little cooler but not cold.
    I checked the lines off the dryer, the top line is cold and the bottom is warm and there is no condensation coming from the dryer at all. CONFUSED AND AFRAID TO TAKE TO CADILLAC DEALER ANY IDEAS???
    (((HELP)))

  5. Great site…I got 2004 envoy XL…only blows hot air an will not switch to def. Or panel seems stuck on floor… did recal did not fix…found 10a fuse Blew put another in an it blows to…any ideas? If i get it pluged in Will it still show code when its blown fuse…need help

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