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.
*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.
Hi Sparky, Does the above procedure apply to a 2010 GMC Terrain? I have digital controls with an Auto button. When I follow the above I don’t see the temp reset. I have also completely disconnected the battery and still don’t see the temp resetting.
I don’t know for sure that the display will react the same as earlier vehicles. According to GM you would need to remove the F12DA fuse in the dash fuse box to initiate the recalibration process. It should have started the recalibrated when you disconnected the battery. You may actually have a faulty actuator.
I have an 04 2500 Duramax. This summer the ac would blow hot from time to time. Turning truck off and back on would normally fix it. Now in the cool days, whole system blows only cold. Have tried the fuse pull routine, didn’t change anything. Is this an actuator issue?
More than likely you do have a temperature door actuator problem. I am assuming since you did not mention any difference between the driver’s and passenger side that your truck has single zone controls? If so the temperature door actuator is located under the passenger side of the dash above the transmission hump in the floor pan.
Replace the actuator on passenger side near t hump. Now I have nothing. BTW duel side auto controls. Can hear the fan blowing, but no air anywhere. I replaced the blend door actuator? Head unit?
Check to see if air flow is improved by switching between fresh air and recirculation. If air flow improves with fresh air and reduces with recirculation you will want to open the glove box and look to see if there is something like paper or plastic on the door grill.
Tried that. Still have nothing. Recirculation button come on, blinks and goes off. Can barely hear fan. No air from anywhere.
Try removing the blower motor and see if there is debris in the impeller blade. Beyond that remove the blower speed controller/resistor and check to see if there is debris blocking the evaporator core air flow.
Thanks for sharing this procedure. I have a 2011 Suburban and I did the recalibration you recommended. Still had the issues so I changed out the drivers side actuator at the floorboard. Still causing me problems so it may be the passenger side. Any idea where that actuator is and how to get to it for a 2011?
Thanks!
It is located under the passenger side air bag assembly. The passenger side air bag and related parts will have to be removed to access the actuator. What is the actual problem that you are experiencing?
When the a/c runs for a while in one setting (regardless of auto/manual) ‘Something’ will adjust and 95% of the air will stop blowing out of the vents. When I turn the a/c on high it sounds like the a/c is blowing air into a closed vent just under the dash behind the passenger air bag. I’ve attempted to recalibrate and change out the lower blend door actuator near the floor. No fix. The only thing that seems to work is either turning off the a/c for 10 minutes or longer. Sometimes if I bang on the side of the console of the a/c controls it also sometimes temporarily fixes the issue.
My first thought would be an iced over evaporator core. When the problem is present open the hood and look for frost on the a/c lines near the firewall.
Definitely not iced over. In fact I was just driving (about 40 minutes in). Turned the air up on manual and sure enough no air blowing from the vents but I could hear air blowing. Just sounds like it’s hitting a closed vent. This time I was able to continually turn the power button off and on about 20 times and ‘something’ adjusted and now I have cold air blowing out of the vents again. Seems to work for a while and then it will act up again.
You will have to determine if the air flow is being blocked somehow or if it is just being diverted to other outlets (defrost or heater vents). It would seem to me if the evaporator core is not freezing up and the blower and blower intakes are okay then the issue has to be with the mode actuator or a broken mode door. Typically when the mode actuator is failing the air flow is simply diverted to an undesired location from the control setting.
I have a 2009 Chevy 3500 diesel. It’s blowing hot on driver’s side and cold on passenger’s side. I tried the re-calibration procedure but nothing changed. Any idea what my problem might be?
More than likely the actuator is faulty and needs to be replaced.
Sparky,
i have a 2007 suburban with auto feature on the ac (and split contols) intermittently ac vents on passengers side (not the drivers side -which seems much more common) will change to hot and seem to be stuck there now. i cant figure out which fuse to pull, can you tell me?
Billy
Not sure why you would want to pull a fuse? I would replace the faulty actuator.