What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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Doubeleive

Wes
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Seems that when I turned mine on the HVAC did some funky stuff and didn’t work right. I would have to try again to confirm what was different.
when I originally replaced the hvac control it was on and I had the dealer reprogram it because the heat wasn't working right and after they did that the display was gone but then someone mentioned turning it on in the forum a while back and I just got around to doing it, I guess I can try turning on heat again with it on and see what it does, what mine was doing before was it was staying cold in the back unless the temp was turned up to 90, if you set it for 89 or less it stayed cold
 

George B

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when I originally replaced the hvac control it was on and I had the dealer reprogram it because the heat wasn't working right and after they did that the display was gone but then someone mentioned turning it on in the forum a while back and I just got around to doing it, I guess I can try turning on heat again with it on and see what it does, what mine was doing before was it was staying cold in the back unless the temp was turned up to 90, if you set it for 89 or less it stayed cold
Mine does that stay cold thing too even with the display “normal” if you get a a chance look at what calibration is saved in that module for me.
 

George B

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when I originally replaced the hvac control it was on and I had the dealer reprogram it because the heat wasn't working right and after they did that the display was gone but then someone mentioned turning it on in the forum a while back and I just got around to doing it, I guess I can try turning on heat again with it on and see what it does, what mine was doing before was it was staying cold in the back unless the temp was turned up to 90, if you set it for 89 or less it stayed cold

Mine does that stay cold thing too even with the display “normal” if you get a a chance look at what calibration is saved in that module for me.
In fact I got into it some here.
 

Doubeleive

Wes
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In fact I got into it some here.
if there is no rear rooftop sensor then it could be one of the ones inside the vent tube, you would have to pull the rear panel off again to get access to it and check it, they are small and are poked into the vent tube with a grommet, they can be tested with a ohm meter and a hair dryer. I haven't head of any going bad they are just a thermistor.
do you have the bose radio?
 

George B

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if there is no rear rooftop sensor then it could be one of the ones inside the vent tube, you would have to pull the rear panel off again to get access to it and check it, they are small and are poked into the vent tube with a grommet, they can be tested with a ohm meter and a hair dryer. I haven't head of any going bad they are just a thermistor.
do you have the bose radio?
Yes, Bose.
 

Doubeleive

Wes
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Yes, Bose.
So then above your head in the headliner there should be 2 little round grills that look like little speakers or mic's, 1 is the ambient temp sensor and the other is the a bose anc mic,
. you said previously there is none in the back? specifically above the 2nd row passenger side seat?
 

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