Rear hvac module discontinued. Can mine be repaired?

[Stickle]

For now I manually set the actuator and unplugged it, all heat all the time. Once I get a replacement maybe I'll crack open the defective one and see what makes it tick (or fail to tick).

 

[Fless]

On my '04 Auto HVAC there are 6 calibrations (firmware) for the front and rear units, 3 each. All of the updated calibrations for these have been issued long ago, and a good scanner will tell you what calibrations exist in yours. Then you can check with your dealer or someone who can program modules to see if yours need to be updated.

Here are my calibrations (not part numbers) when I read them with my Tech 2, when I had it.