2005 Yukon: Recirc door "works", but won't activate during use

[DenaliDoofus]

TLDR: Recirculator door "works" when I do the reset (it moves back and forth during calibration), but when I press the button, the recirc door doesn't open and stays in vent mode. Light turns on and stays on, but door physically doesn't open

Longer Version:
Recently picked up a 2005 Yukon XL Denali and the AC seems to be stuck on vent and won't go recirculate air (even when the button is pushed and light is on). I was able to get in and replace the recirculator door actuator (man was that a challenge), but it still didn't seem to work. When I was replacing the actuator, I moved the door to see if it might be stuck like I'd seen on other threads about the door getting stuck and while it was a bit stiff, it did move freely.

After I replaced the actuator, I cleared the codes and did the "reset/calibration" (remove the fuse, wait, turn back on, wait) and during the recalibration process, I can see the recirculator door move back and forth on its own. However, when I go to put it in recirculate mode under normal use (press the recirc button), the light will turn on, but using a boroscope, the blend door doesn't actually move and stays on vent mode. The light does stay on and doesn't blink at all; I moved it into defrost mode and tried to recirculate, but it will blink to show the mode isn't compatible, and when I move it to blow on the face like normal, recircualtor still wont work.

I feel like I'm 85% the way there; the computer can move the door like it does during the reclibration, but I still can't make it work. If someone can please help me with figuring out how to actually recirculate, I would greatly appreciative it!

 

[latvius]

Sounds like the control panel either isn't sending the signal to the actuator when it should or it is and the signals not getting there.

 

[Fless]

The HVAC unit might need an updated calibration (programming).

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

@swathdiver may be able to give you some troubleshooting pointers to get you to 100%.

 

[DenaliDoofus]

TLDR: I think I figured out the "issue" (vent position puts count out of count range), but still haven't found a good solution. I have an idea for a quick fix, but would love ideas for a long term fix.

Longer Version:
I searched all night and found a youtube video that had the same problem as me (

) and in the comments the original poster "figured it out" and mentioned "I had this problem too and finally figured out how to fix it. The allowable actuator travel range is from 5-250 Counts. Mine measured 0-212. So, 0 < 5 sets the DTC B0229 – which closes the door and deactivates it." Sure enough, I checked the error codes with my Bluedriver and I had error code B0229.

Since I still had my dash cover off, I went and stuck a 1/2" socket extension into the vent position side during the recalibration (picture attached) and though the door got tight on the extension, it wasn't able to close all the way and sure enough, the recirculation function worked!!! I was able to push the recirc button on and off and the door would move to recirc and vent. However, when I pulled the sock extension out, the door closed all the way, threw up the B0229 code and stopped working. ARG!!!! I'm guessing when the door fully "closes" in the vent position, for whatever reason that location is in the 0<5 count range which throughs the B0229 error code. I was hoping the recalibration with the socket in there would space the minimum to something higher than 5, but it looks like it tries to close all every time it actuates.

My "quick and dirty solution" idea is to 3D print a cylinder similar to the size of the socket and stick it in there with some duct/gorilla tape to make sure it doesn't pop out, but I would love to hear any ideas on how to make a more "permanent and real fix". I'm relatively new to cars and so I have a BlueDriver for reading codes, but not much else in the way of diagnostics or programming tools.

Thank you all for your input!!!!

P.S. Going to try to paint the truck next few weeks, so I'll post some pictures of the end result after when it gets purdy.

 

[latvius]

Here's some similar info on a 2004 Sierra, I seem to remember reading about someone putting a screw in the actuator to make a hard stop for it.

https://www.silveradosierra.com/threads/recirc-door-actuator-over-ranging.701370/

 

[latvius]

Also found this like fless said updating SW. The short is the foam shrinks on the door allowing it to move to and far and throw the code. SW can be updated with new range travel. Or looks like you could do the shim to prevent actuator from moving too far.

Oh one other thing on the new actuators I was told if they go beyond limits it's toast and won't go back even if you take it apart and move it back. The originals you could take apart and move them manually. FWIW