As many of the other reviewers have written this module does not fully support auto mode and runs on when the ignition is turned off. I purchased this module because I had an issue with the rear air in my 04 Tahoe randomly blowing hot instead of cold.
The module did resolve the issue with the blend door. However, when on auto mode it only changes the temperature not the fan speed. The fan will run full blast non-stop. Also, when the ignition is turned off the fan will continue to run until either the door is opened or you can manually turn the overhead control from Auto to Off. Disappointed this did not restore function to OEM.
I’ll probably end up looking for a used module and cross my fingers it lasts a few more years. This is really an overpriced band-aid. I should have trusted the other reviews. I’d give it one star but it halfway fixed my problem. The part that makes me the most upset is that Dorman markets this part saying it restores original functionality which is totally dishonest and misleading.
If you’re looking for only basic functionality to be restored and you’re in a hurry this will probably work for you but don’t expect it to operate like the original.