I have a 2011 GMC Acadia and the blend door actuator on the driver side was not working; stuck at high heat. I bought a replacement from my local Chevy dealer and installed it, and did the recalibration process, removing the fuse for 30 seconds, replacing it, and then starting the vehicle and allowing it to calibrate. I can see the actuator move from the hot position to the cold position and then back during the calibration process. However after completing the calibration, the actuator seems to be stuck on hot again. I used a 9v battery and can adjust it open and closed, it moves freely, but it is not responding to the temperature adjustment on the dash. I’ve done the calibration several times, allowing extra time, but nothing seems to help.

Does anyone have any ideas? What other troubleshooting could I do? Any idea what could be causing this or how to fix it? I would really appreciate anyone’* input.

Can you look at live data of the HVAC module? Need to see what the temp sensors are doing.

I don’t have a scanner that can view the HVAC module. I do have a USB OBD2 module. Is there an open source or free software that will allow me to scan that?

No open source that I know of but you can get a fair scanner that will pay for itself in short order for a 100 bucks thereabouts.
Here'* a popular one.
https://www.ebay.com/itm/401694005606

I have one of “those” as well as a Bluetooth one and a USB one, but to my knowledge, none will scan a BCM, or similar specialty modules like the HVAC module in question.