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”

  2. I did this and now it comes out AC comes out front vent and is cold for a little and then drivers side goes hot which I know there is a blend door but why does it blend to hot?

  3. This happened to me on my 2005 silverado crew cab after changing the battery. My attempt did not work but I found out that there are two HVAC fuses. One is under the hood as stated and there is another in left side dashboard marked HVAC. It didn’t reset till I removed both of them then followed Sparkys procedure. Mine is automatic temp for both sides indivually set.Thanks for the info and I hope this helps other people.

  4. This worked for me! Have a 2005 GMC Sierra with climate control. At first my AC temp would say it was on 72, but the fan would not engage. I could feel cold air barely coming out the vents, but it would not blow. I replaced the HVAC module for about $100. This fixed the fan issue, but the driver’s side was blowing hot air while the passenger side was cold. I used the steps above and it fixed it. No meat freezer air is coming out both sides. You just saved two educators a lot of money. Thanks.

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