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.
Gremlins…
I removed the hush panel to expose the actuator. Unplugged then plugged back in. Did the recalibration steps. Lo and behold, everything is working as normal. Thanks for your help.
Drew
It is a common misconception that the battery disconnect causes the actuators to go bad. Instead there is already a fault within the old actuator that gets revealed when the battery is disconnected and the recalibration process is begun. Most professional mechanics that have already experienced problems like this, install a backup battery when the vehicle’s battery has to be changed.
Thank you Sparky, ill try that. One more question…how would changing the battery have made the actuator go bad?
Drew
Ok, just tried again, and same results. I would say that the passenger side and rear controls work and blow cold. The drivers side blows only hot air, and you can change from dash, to floor, to defrost with no problem, but only hot air.
Drew
Pull the passenger side hush panel and disconnect the lower actuator while it is in the cold position. It will stay there until you can replace it.