2008 Yuke - AC blows hot on driver side, cold on passenger side - Dealership says problem cannot be solved?

[mikez71]

In my case, I had a bad manual HVAC module. I could adjust the rear mode/temp partially, but after a minute or so would quit.
It would not work again until I unplugged the battery to reset.

Looking at a Tech 2, I could see actuator commanded position and actual position, and they were not matching up. (going backwards direction)

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"Other than that there were no codes or odd sensor data."
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ACTUALLY there WERE actuator codes.
Just wanted to clear that up. Was the code saying position circuit out of range. I forgot about that.

I ended up purchasing another used HVAC module from ebay, and that one worked perfectly.

 

[Geotrash]

Did that. No results. Same issue. Checked signals on the wires to the actuator and the signal was good and correct, new actuator didn't work, bench checked them to prove they were working and still got a fail. I've concluded that the dealership techs/mechanics haven't a clue because this seems to be a common issue and servicing the issue only costs customers more and more money until they give up. And the problem is that to get at the actuator (once again) I have to tear out the center console (once again) myself and remove the driver's seat just to get the center console out (once again) just like the dealership had to do. So I got charged an S-load of money for a problem that still isn't fixed and they have their hand out for more money for a problem they can't fix by their own admission.

We're going to keep throwing stones at the wall until you answer two key questions:

1/ Do you have a Tech 2 scanner or equivalent that will show you the commanded vs actual position of the actuator and blend door? If so, what does it show?

2/ Is this an automatic climate control or manual HVAC system?

Finally, I would not rule out faulty parts or a faulty HVAC module as others have said. We see faulty parts here frequently. Sometimes they test okay on the bench but fail once installed.

 

[swathdiver]

Problem:

Had to get a new battery (reset the battery routine in the computer), now HVAC is messed up. Hot air through driver's side, cold air though passenger side (as normal). Dealer said nothing is wrong and they have no clue about the problem or how to solve it. Checked the blend door and there is no problem with the blend door (replaced it, had wiring checked, had computer checked, everything). Dealership is absolutely clueless.

Every reset method for the blend door tried did not work.

Is there some secret to resetting that blend door? Nothing I have read on this forum works.

What is the part number of the driver's side actuator that was replaced? Have you visually verified the part number yourself?

Dealership is lazy and put their newbs on it, not the experienced guys.

 

[ivin74]

Yes they did. It had no effect. Like I said, they did everything diagnostically - checked the wiring, computer, components, you name it. Still does the same thing.

Sounds like the AC module is bad then. The module sends the command to the actuator. Like others have said. Do you have a tech 2 to diagnose the problem. These AC systems are basic and should be easy to diagnose. I can't believe the dealer could not fix the issue.

 

[Fless]

Bypass the dealer and get a capable scanner that will show the live data for the actuators. It'll pay for itself in a couple of uses.

As @Geotrash noted, a comparison of the commanded vs. actual position count should tell you 1) if the actuator is responding according to what the HVAC module is commanding and 2) if the HVAC module is commanding the proper position.

 

[Luvsbaby]

Problem:

Had to get a new battery (reset the battery routine in the computer), now HVAC is messed up. Hot air through driver's side, cold air though passenger side (as normal). Dealer said nothing is wrong and they have no clue about the problem or how to solve it. Checked the blend door and there is no problem with the blend door (replaced it, had wiring checked, had computer checked, everything). Dealership is absolutely clueless.

Every reset method for the blend door tried did not work.

Is there some secret to resetting that blend door? Nothing I have read on this forum works.

Hello!
I had the same problem with my 2005 Yukon-XL (aka, 'Ruby). It would work fine and then sometimes it was start blowing hot air on the driver's side. And my mechanic kept thinking it was the weak compressor, but as time went on her diagnosed that it was the actuator and that did the trick! Hope this helps.