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

[Gildan]

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.

 

[j91z28d1]

a tech 2 has a proper reset function. but without one. I've seen a few threads in here have luck with taking both battery cables off, touch them together for a few minutes.

hook back up, click the key forward, and don't touch the havc controls for a minute or so. they should go thru a reset procedure

 

[Gildan]

a tech 2 has a proper reset function. but without one. I've seen a few threads in here have luck with taking both battery cables off, touch them together for a few minutes.

hook back up, click the key forward, and don't touch the havc controls for a minute or so. they should go thru a reset procedure

Tried that one. Dealership tried that one. Works for about an hour and hot air again. You hear a reset for about two seconds and then nothing. I hear a brief reset and then it works for a few minutes, then the hot air again.

 

[j91z28d1]

if it works for a while and then loses position reference. I'd guess the encoder inside the blend door is bad. or worse case the module?

I don't know man.. and it doesn't have any codes. dealer techs don't really like to spend the time. but there's a full walk thru of the wiring and testing each thing in their software.

is this a auto hvac? @mikez71 did a auto to manual hvac unit swap on his. he might have an idea?

 

[ivin74]

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.

Did the dealer replace the hvac actuator that is not working properly or did they just reset it?

 

[Gildan]

Did the dealer replace the hvac actuator that is not working properly or did they just reset it?

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.

 

[Doubeleive]

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.

either the actuator under the glove box is going bad or the environmental sensor in the headliner above your head is goofy (presuming you have auto ac)
it's not rocket science, if that fails to resolve it then the ac control head is funky
it's almost always the actuator though, swap it out if that doesn't fix it return it
you need a 7mm deep socket and 5.5mm, takes about 20 minutes
it's almost the same exact procedure as the gmt800's

 

[Doubeleive]

and the dealer should know better they work on this stuff all day long, the same problem has happened since 2000 or even before
the actuaotor has a little motor & gear inside and a copper strip. the strip conducts ohm's and the ohm reading is what tells the hvac control what position it is in and what position it is being commanded to. over time of moving back n forth hundreds of times the copper strip gets worn, grease builds up on it etc. then it either gives the wrong ohms or the motor & plastic gear wear out or break, jam, etc. and walla problem!

 

[Gildan]

either the actuator under the glove box is going bad or the environmental sensor in the headliner above your head is goofy (presuming you have auto ac)
it's not rocket science, if that fails to resolve it then the ac control head is funky
it's almost always the actuator though, swap it out if that doesn't fix it return it
you need a 7mm deep socket and 5.5mm, takes about 20 minutes
it's almost the same exact procedure as the gmt800's

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.

 

[Doubeleive]

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.

ok so need more information
is it manual hvac with knobs you spin or is it auto ac with the digital controls?
in either case there is no need to take the center console out for anything, nor the drivers seat

 

[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)

------------------
"Other than that there were no codes or odd sensor data."
------------------
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.