02 Yukon Climate control gremlins

Hi there!

I got a few grelims on the climate controls on the 02 Yukon, nothing outrageous. I don't know how these work yet, do they run off vacuum or if they electrically actuated... (well I think I have figured out that part... sounds like electric) ?

Issues:

1) Few weeks ago when I plugged in my scanner the only code on the vehicle left was a B3761 Code – Air Flow Control 3 Feedback Circuit Short to Ground or Open.. I figured that was from battery drain and restart but maybe that points to something.
2) AC button needs a heavy press and takes many attempts to light on/off, but the ac works well when ON
3) Heat doesn't work unless it's turned all the way to the right past the red mark in Full Heat mode
4) Only blows through the dash vents. Doesn’t blow out of the floor or defrost. I can't quite tell if it's the actuator or the controls (Any tips on telling which may be faulty? Any tests on Tech2?). Actuator part number on driver side 52473356, passenger side 52474810.

While I am able to deal with these problems as things are still sort of functional, figured I would at least start a thread to 1) document what problems I'm having, record codes, pictures 2) see if this issue is common and get an idea of what it would take to fix.

My climate control module part number is 15126604 and sure could use a new one... I am usually into buying OE parts only. But good luck finding one. Any reasonably good quality replacements you have had good luck with ?

@swathdiver may be able to provide some input and perspective on your issue.

I had time to play with this some more... I was able to command the mix and mode doors to the positions with my scan tool, but the actual climate control module (CCM) is unable to do the same, so I assume the problem is with the CCM ?

Also, dealer provided part # for my VIN for the CCM is 15126604 whereas what I found installed was a 15060162, with manufactured date of 10May02. So this could be the original.

Installed another 15060162 that came off eBay. Used module but it works better than my old one and now all my buttons are working finally. Still no response from the blend door actuator. So next step is to replace those suckers. Parts cannon time I guess (cheap parts so why not).

Got the new blend door actuator... before I installed it I wanted to see if it responded. I simply connected the harness to it and adjusted from heat to cold. I could see response if it was in the high seat setting, and back to cold, but no response anywhere else... Just like my old one so its not the actuator ....

I'm really starting to think this TSB applies to me... improper routing of C206 (RPO C68)

Update....

This morning I was playing with the scan tool again. I removed and reinstalled the control module with the blower controls in off position. After turning on vehicle, I could hear the temp blend actuator go through the calibration... I let it do its thing for 1-2 mins. Now the temp works.... It is really show though. Is the temp actuator known to be really slow usually ? I can see the scan tool and see the command/actual track really closely... all functioning but SLOW

Still no mode actuator.....

I am able to command the mode actuator from my scan door and it works well.... but after reading the thread below with very similar symptoms and the fact that I have a DTC (B3761), I'm going to try a new mode actuator...

The issue has been resolved

Finding the fix was a rather frustrating trial and error process, and after a new mode door actuator was installed... Dorman 604-113.

There are 2 limit positions for the actuator, Defrost and Dash Vents... The problem is that when you disconnect the battery and reconnect, the control module goes through a calibration and expects the actuator to physically be in the Defrost position or somewhere in the middle and definitely not in the dash position (calibration takes it to the dash vent position and back to the defrost, so if it was in the dash position to begin with, it would hit a hard limit and set a code... and with enough attempt it probably bricks the actuator.. I guess that is B3761?) ....

Any way long story short, I installed the new actuator (arrives in a middle position between defrost and dash), so after installing worked.... well I disconnected the battery to check something else... and when I got back to it, the actuator didn't work and I saw what physically was happening during the calibration process, and how I figured what was going on.... so I had to remove the actuator again, use my scan tool to set it in the middle position, reinstall it

So... from here on, I need to ensure the actuator is in the defrost position before messing with the battery...