Problem with 2001 Tahoe with HVAC. Mode selector goes into default(only defrost)

What started off as my heat only blowing on the face vents, now the system is in default.
I repacked the mode actuator with a GM one and tried to calibrate it ans after installation it only goes to defrost.
I thought it might be a bad control panel bought one and now when you plug the new one in, it cycles thru all the cycles and Iowa back to default.
At first I was getting a BCM code of a aspritator only to find out mine was unplugged. I plug it in and now the code is gone but still only defrost...
Has anyone experienced this before. I am completely lost right now and I even had a friend from Chevy look at it on a GM scanner. He manually opened all the blend doors and when you shut the truck off back into default...

probably needs to be reprogrammed (software flashed) not just calibrated.

Doubeleive said:

probably needs to be reprogrammed (software flashed) not just calibrated.

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What do you mean reprogrammed.
This year truck can not be programmed off a scanner.
Is there a different way

it say's computer climate control right? so I assumed it has to have some kind of firmware, if it cant be programmed with a tech2 then I don't know, I had replaced mine in my 2012 this summer and everything worked fine until I needed heat then after screwing around and spending time and money i found out it needed to be flashed with the correct firmware it was looking for input from a temp sensor I didn't have and would default to cold unless I turned the heat all the way up, maybe you have a funky sensor? I thought I had a bad sensor because it kept giving me a open code for rear temp sensor 2, after poking around the entire internet couldn't find any reference to rear temp sensor 2 so I figured maybe it was one of the ones in the vent housings and they tested good, finally found a diagram showing some trucks having a rear temp sensor just like the one above the driver (on the 03+) only mine didn't have it

This is what my control panel looks like ...

No codes...

ok so it has "auto" which means you should have temp sensors, have you checked those? they should have 5v power to them and they should have resistance that changes with heat applied, I would suspect that is either not getting a reading or something is shorted but that should give a code I would think. a tech2 should able to see those readings and what the temps are and what is desired.
does it have separate rear heat control?
seems weird that it would have auto / computer control and not take firmware
have tried looking for any tsb's that describe this problem?
just trying to help, not an expert!

Whitelx1 said:

No codes...

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I just fixed mine. Did you already replace the mode actuator that is really hard to get to above/to the side of the gas pedal? The blend door actuator is under the passenger dash and will not fix the issue you describe. It is a bear to replace without removing the dash but I did it with I believe a 5.5 mm socket/wrench and kind of rigged to get the bolt at the top.