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.

 

[Stickle]

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.

View attachment 443208

I've come across a few mentions of calibration, lots that seem to say the mods are plug n play. Funny how a mass produced part like this can remain such a confounding variable after all this time.

 

[Fless]

I've come across a few mentions of calibration, lots that seem to say the mods are plug n play. Funny how a mass produced part like this can remain such a confounding variable after all this time.

The Dorman (and likely other aftermarket brand) modules will probably have the latest calibrations; they should be marketed as PnP if they are. GM hasn't issued new calibrations for these for years, so they're static at this point, and if the aftermarket mfr. uses them it'll be the latest. If you pull a module from the junkyard it may or may not have been updated.