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 recently purchased an 03 chevy suburban. I went to replace the radio, saw that the Original Owner cut the OEM Harness out and hotwired the radio they had in. I got an OEM harness out of a suburban in a junkyard and my brother and I set about to restore the harness. We did that, got everything connected and closed everything up. Well the a/c started acting funny. Won’t blow cold air and fan blower cuts at setting 5. I did this calibration method and now the fan blower does not kill at 5 BUT it is still blowing hot air and the rear a/c won’t blow….I got this vehicle to be spacious enough for my four kids and fiance and this electric problems make me wanna junk the car. Any help would be appreciated.
Okay, a recalibration will not correct blower speed issues so that was a coincidence and most likely the real problem with the blower speed issue is a faulty connection at the blower resistor. If performing the recalibration procedure does not correct the no cold air issue and there is not a problem with the compressor or refrigerant system I would suspect a faulty temperature door actuator. I am assuming you have a single zone front HVAC control panel. If so the actuator is located under the passenger side of the dash. AS far as the rear blower goes I would start with checking the fuses.
For the front, I changed the actuator and I have dual controls. I have cold air restored BUT the fan blower still cuts at 5. I am going to trace the wires from the resistor to wherever it goes.
The rear, I have checked all the fuses and none are blown. I checked the blower motor by running a wire from the rear connected to the blower to the front jumping off of the resistor and the fan comes on. I changed the rear resistor to ensure that was not the issue but still got nothing.
I did notice that the wire harness for the rear a/c that is located behind the kick panel had a burnt orange wire and the harness was scorched. I went to pull a part and took the harness out of there and tried to splice the wire together with the wire out the harness I pulled so that “technically” I would have good connectors in the harness cuz the ones already there were burned up
Glad to hear you are making progress.
Ok so I have a 2004 GMC Sierra 2500hd and the passenger side hot and cold manual switch gets stuck on hot. I’ve done the fuse reset for the HVAC system but my battery died over the weekend and it went back doing the same thing. Does this mean that I will have to get a new actuator for the manual climate control or am I going to have to keep doing the fuse trick to have control over the climate on the passenger side?
Maybe. Given the age of the vehicle there is a reasonable chance that the actuator is failing. However even with all new actuators if the battery memory voltage is missing and then re installed the recalibration process begins again. It is the same as removing the fuse. So I would recommend repairing the dead battery condition first.
Hi,
I have a weird one. I replaced my HVAC Control Module on my 2003 Chevy Suburban. After replacing the module it displays the external temperature in the module. I used to have the temp displayed in the rear view mirror. The temperature that is displayed in the module is about 40 degrees off in the hot range, for example today it was 70 degrees but the temp displayed in the module is 118 degrees. I think this has an affect on the operation of the HVAC system, for example, this morning it was about 43 degrees but the display on the module showed 82. I was not able to get any heat as I think the module saw 82 and said nope, I am going to give you AC. I tried to re-configure the module by pressing the defrost and power button on the module but no-go, it would not get to a prompt where I could re-configure it. Any help here would be appreciated and thank you for listening.
Can you provide the part number of the installed part?
I own a 2007 GMC Sierra 2500HD, NBS, SLE trim, extended cab, 4WD, diesel pickup with approximately 199K miles.
The truck has automatic HVAC controls with very dim LED lights. I plan on replacing it soon with a Dorman module 599-189.
Can you please give me the HVAC Actuator Recalibration Procedure for this truck?
Since you will be replacing the control panel all you have to do is start with the ignition off. Replace the control panel and turn the ignition on for a full minute. Do not touch anything during that one minute time period. Turn the ignition off for at least 10 seconds but no more than 30 seconds. Start the engine and check the system operation.
Thanks for the fast reply and the procedure.
Sparky needs some guidance. Got a 07 Burb Z71 that is barely blowing in front if at all. Rear is good and defrost seems to work. I just finished replacing the mode, recirculation, & left temp actuators as well as recalibrated it. My fuse box doesn’t have HVAC/ECAS so I pulled the HVAC/Batt & HVAC/IGN (both are 10A). Still nothing. When it does blow it’s the proper temp. Any ideas?
On your vehicle you would need to remove the HVAC/BATT fuse number 38 in the underhood fuse box to initiate the recalibration. However it sounds like you have a blower type issue instead. Can you clarify? You stated that the temperature control is fine. Can you also confirm that the mode function is also working (defrost, vent and floor)?
So i replaced the mode actuator and then watched it move successfully from each mode. However it’s barely blowing out the front upper or lower vents. The rear had no issues at all
Is the front air flow also low through the floor vents?
Yes
So it sounds like you do have a blower issue and not a vent control issue. Now I need to know if you have auto or manual controls? Also this would be much easier to keep up with if you would open an Ask a Question session.