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.
I just did this procedure and now no air is coming out of my vents; only the defrost vents. Any suggestions?
Would need to know year, make, model and type of a/c controls (auto or manual) in order to help.
Great website!
I have a 2016 Yukon XL Denali. The rear AC is ice cold, my front blows warm air (both driver and passenger side). The front basically blows ambient air, sometimes it’s a bit colder than other times. When I switch to heat, it works perfectly in the front and rear.
I precisely performed the recalibration procedure a couple times without any luck. I assumed the issue was one of the blend door actuators, I was hoping the reset would correct the issue. Unfortunately I wasn’t one of the lucky ones.
Do you think the issue is one of the blend door actuators? If so how do I determine which one it is? What else could cause the front to blow warm while the rear blows ice cold?
In order to perform a recalibration on your vehicle you will need to remove fuse F28DL in the left interior fuse box and then follow the normal procedure. If it does not work also try removing the F24DL at the same time as the F28DL fuse. Something else to look at is the temperature of the suction lines coming out of the front and rear expansion valves. After about 5 minutes of run time the lines should both be equally cold.
Thank you, using those instructions it did recalibrate correctly. The auto temp changed when I restarted the vehicle. Unfortunately the front AC is still not even close to as cold as the rear AC, it’s just slightly cold.
I’ll check the suction lines as you recommended. If those are not equally cold what’s the fix for that?
Checking for a correct refrigerant charge level (a/c machine needed) or a faulty front expansion valve.
I’ve tried this once and it didn’t help. But I just recharged my AC so I’m going to give it another go this morning. My 03 Suburban is throwing ice cold AC in the back but hot in the front. I recharged the AC yesterday and it started to blow cooler are, but not cold. Stupid me played with the heat to see if it was blowing the same temp are if I put the heat on. Which it doesn’t. Now its blowing hot air in the front again. I’m going to try the reset again, but I’m thinking it may be the blend door. Any ideas on if may be something I’m missing?
Sounds like you may have two problems. The refrigerant charge level is off and you have a blend door issue. I am assuming that you do not have dealer level scan tools and an a/c machine so my two best suggestions would be to remove the driver’s side temperature door actuator located under the passenger side of the dash. Then manually turn the door to see if full cooling can be achieved. The other would be to feel both a/c lines at the firewall and see if they are both equally cold after about five minutes of the system being on.
I have an 05 Silverado 1500 5.3. Everything works fine except the blower recently started blowing air when on speed 0/off position. The air only comes out of the duct in the center just to the right of the radio. The temp changes when I control it and the speed changes when I go through the speeds. What could be causing it to be doing that and only through the one duct? Everything shuts off when the key is off so I dont think it’s the resistor but I’m not sure. Can it be reset or fixed as it sits or do I need to replace the module and or the resistor?
If it is only there while the vehicle is moving it would be normal ram air. Other than that disconnect the blower motor and see if it goes away. If it does then I would say either the blower switch or the resistor has an issue.
That was my first thought but it does it while stopped. I will do that and go from there. Thank you for your time
I gpt a 2006 trailblazer ac was work fine checked today compressor wasn’t working system was little low so charged it up compressor works.But know i got hot air out of all vents no cold air
If the battery was disconnected recently the system went into recalibration mode and likely revealed a faulty mode door actuator. Regardless I would try doing the recalibration a few times and see if it will recover.