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

[Geotrash]

my other cars with auto I may adjust 2 or 3 degrees up or down depending on summer and winner. but this yukon? can't do it. the auto programing is just awful for me. when I got the truck the buttons looked brand new. not a week later completely worn off. it's just never the right temp. or blowing super loud for nothing.

maybe it's my truck? the Temps from side to side basically do nothing either. you can have a 10deg difference in temp and not tell a single difference. plus I gotta hit recirculate ever time. if I forget, not 5 mins into a drive I got some no cat having Ford work truck stinking me out and then it takes forever to get the air out.

these are all things I have zero problems with in any other vehicle I drive. even older or newer gm auto systems.

could also be we get big temp swings here, it can be 50 on the way to work and 115 with a inside temp of 160 on the way home. but still, my other cars handle it just fine.

Yeah, makes me wonder if one of your sensors is off, or maybe there's something weird about the climate control system in the hybrids.

 

[j91z28d1]

No clue. But it looks like it was run over by a thousand other cars before I hit it just right.

I had a compressor with me but the tire was losing air so fast it was useless. In our LR2, I have one of these, which would've worked to seal and then inflate the tire: https://a.co/d/eMbJyC0

mine came factory with something just like that. little compressor with 2 hoses, one puts sealer in it and the other side airs it up. I've never used it, but it's still in there.

wouldn't supised me if the sealer is junk by now thou haha. I'm going to keep one of the best tires and either go hit up a junk yard for a spare, or if I get lazy just hit by now. it does come with all the stuff, like different exhaust resonator and heat shields. but blah, full size trucks and suvs really should come with a full size spare.

 

[j91z28d1]

Yeah, makes me wonder if one of your sensors is off, or maybe there's something weird about the climate control system in the hybrids.

could be.. it doesn't give me any hvac codes..but I have notched one of the blend doors getting noisey. but I have wondered if there's more air flowing into the cabin than normal, since the air cooled battery is under the seat, with an exit to outside behind it. there's some old threads about how to cool your battery down faster but taking off recirculate put full cold to the floor and let it suck in cool air. but I've got lithium batteries they don't run hot like the oem ones did. driving this truck without recirculate on reminds me of the motorcycle days, can literally smell everything outside. get behind a old Ford lawn service truck and you'll be light headed in no time.

I did realize the rear temp will match the front if you turn rear off and on thou, but normally it's the kid in a car seat asking for more or less air blowing down on him. so I gotta find the fan speed button from the front seat.

 

[CaptainAmerica1]

naw I just drive where others do not and I am always picking up hardware

This is why I stopped passing dumbshits on the shoulder, kept getting flats.

 

[Geoffsfas10]

mine threw the P0340 code today. whole thing was weird. drove it back to my office from a site visit, ran inside, dropped off some stuff, came back out maybe 5-10 minutes later, started it up, seemed fine, and CEL. Got the code reader and P0340, camshaft position circuit...ok. cleared code and its been gone since then. truck starts, idles and runs fine. Im going to mess with the wiring tomorrow, some brief looks it seem part of the harness that goes to the sensor MAY have been sitting funny on part of the sterring rack bushings, and maybe rubbed it some, but this seems like a one off code and I shouldnt be super worried about it.

 

[pwtr02ss]

I got a rattle in the rear end that is driving me FKN NUTZ!!!!!!!!!

Only on washboard surfaces like rough concrete pads. Sounds like the right rear. I found a nut missing off a rear sway bar link, swore that was it. Replaced it, still there. No play in the links at all. No play in shock mounts or hardware. Spare tire heat shield is intact, properly mounted and secure.

Replaced worn exhaust hanger bushing, still there. I got pissed off and removed the spare and winch over the weekend. I was under there pounding on the frame/exhaust to try and duplicate the noise. The vapor solenoid on the rear crossmember above the spare has a little bit of looseness but I don't think that is it. I am getting some rattling from the rear bumper cover against the steel under bumper/hitch. And driving without the spare the rattle is still there.

My right tail light housing had a rattle due to worn out rubber grommets. I used a few dabs of silicone adhesive on the ports to tighten that up. Rattle is still there.

I am thinking of injecting some silicone adhesive between the bumper step and frame to create a cushion and see if that clears it up. Grrrr.....

Have you replaced the sway bar links in the back?

 

[pwtr02ss]

my other cars with auto I may adjust 2 or 3 degrees up or down depending on summer and winner. but this yukon? can't do it. the auto programing is just awful for me. when I got the truck the buttons looked brand new. not a week later completely worn off. it's just never the right temp. or blowing super loud for nothing.

maybe it's my truck? the Temps from side to side basically do nothing either. you can have a 10deg difference in temp and not tell a single difference. plus I gotta hit recirculate ever time. if I forget, not 5 mins into a drive I got some no cat having Ford work truck stinking me out and then it takes forever to get the air out.

these are all things I have zero problems with in any other vehicle I drive. even older or newer gm auto systems.

could also be we get big temp swings here, it can be 50 on the way to work and 115 with a inside temp of 160 on the way home. but still, my other cars handle it just fine.

I bet one of your temp sensors is going bad. I had issues with mine and replaced the sensor in the headliner. Back to normal now

 

[j91z28d1]

I bet one of your temp sensors is going bad. I had issues with mine and replaced the sensor in the headliner. Back to normal now

next time I have the tech 2 out I'll see if I can pull up temp sensors. I don't know that it displays them all. I know there's a few around the truck.

 

[j91z28d1]

I bet one of your temp sensors is going bad. I had issues with mine and replaced the sensor in the headliner. Back to normal now

I just took a look at the diagrams, yeah it's basically a completely different hvac unit in the hybrids. there's it's own 4 pages of diagrams just for it. looks like it might have one more temp sensor and a few more control outputs for extra electric water pumps, 3 speed cooling fans and the electric ac compressor gets a pwm speed control for the compressor rpm. plus a few more odds and ends.

I'll park it in the shade one day with the windows down and let all the Temps equalize. see if I can find one that's off compared to the rest. wouldn't surprise me, but it also wouldn't surprise me if they just did a bad job program it haha. to focused on run time in auto stop vs idling. I have in the past noticed the ac rpm is much lower when stopped than it is when rolling which I thought was weird at the time, I thought maybe trying to mimic a engine driven compressor but other electric compressors I've since looked at data from don't do that.. they adjust speed by pressures needed.

maybe another side effect of gm basically putting a 90s technology nickel metal hydride prius battery in a full size suv and then struggling to make it last 8 years. still feel that was down fall of this truck. if they would have used better in house battery development going on at the same thing frame, these would sill be a thing and getting 30mpg around town.

/rant

 

[89Suburban]

Have you replaced the sway bar links in the back?

I gave them a neck choke shake and they did not to seem to have any play.

 

[pwtr02ss]

I gave them a neck choke shake and they did not to seem to have any play.

I mention this because Steph's old escape had a rattle. I replaced the full strut assemblies and new shocks. Still had a rattle. Replaced the sway bar links and it went away. They were the style that has like a ball joint on each end. They felt tight and fine, but were worn. Prob not the problem but it's one more thing to check

 

[Doubeleive]

I just took a look at the diagrams, yeah it's basically a completely different hvac unit in the hybrids. there's it's own 4 pages of diagrams just for it. looks like it might have one more temp sensor and a few more control outputs for extra electric water pumps, 3 speed cooling fans and the electric ac compressor gets a pwm speed control for the compressor rpm. plus a few more odds and ends.

I'll park it in the shade one day with the windows down and let all the Temps equalize. see if I can find one that's off compared to the rest. wouldn't surprise me, but it also wouldn't surprise me if they just did a bad job program it haha. to focused on run time in auto stop vs idling. I have in the past noticed the ac rpm is much lower when stopped than it is when rolling which I thought was weird at the time, I thought maybe trying to mimic a engine driven compressor but other electric compressors I've since looked at data from don't do that.. they adjust speed by pressures needed.

maybe another side effect of gm basically putting a 90s technology nickel metal hydride prius battery in a full size suv and then struggling to make it last 8 years. still feel that was down fall of this truck. if they would have used better in house battery development going on at the same thing frame, these would sill be a thing and getting 30mpg around town.

/rant

you shouldn't have to do that, in the tech2 there is a function to check the sensors/actuators and it just shows "actual" VS "commanded" the outside temp doesn't matter
it goes by what is being commanded and what it is reading inside. I mean I guess if it's -40 out and you are trying to get a halfway decent reading it could throw it off I guess.
windows should be closed because it is reading the inside "controled" environment, rolling the windows down is going to throw another variable in.
the "auto" function reads data off of the headliner and duct sensors, so that's what you should be monitoring once you have established that the actuators are working properly.
there are several small "thermistors" inside the duct's in various locations but one of those being bad is likely rare but easily tested with a blow drier and ohm meter.
more of a PITA to find those than anything, your headliner sensors are going to be the most problematic they have a little fan inside and get worn/dirty.
I would set it for like 77 and then let it get all warmed up with the windows up (for like 15 minutes of driving at least) and then go thru with the tech2 and check each one actual/commanded.

 

[Grady_Wilson]

my other cars with auto I may adjust 2 or 3 degrees up or down depending on summer and winner. but this yukon? can't do it. the auto programing is just awful for me. when I got the truck the buttons looked brand new. not a week later completely worn off. it's just never the right temp. or blowing super loud for nothing.

maybe it's my truck? the Temps from side to side basically do nothing either. you can have a 10deg difference in temp and not tell a single difference. plus I gotta hit recirculate ever time. if I forget, not 5 mins into a drive I got some no cat having Ford work truck stinking me out and then it takes forever to get the air out.

these are all things I have zero problems with in any other vehicle I drive. even older or newer gm auto systems.

could also be we get big temp swings here, it can be 50 on the way to work and 115 with a inside temp of 160 on the way home. but still, my other cars handle it just fine.

I picked up my Yukon with 113k miles on the clock and the only HVAC button that had any wear was the power button.
Mine seems to work OK, but not as nicely as the auto climate controls in my 2017 Kia Optima.
My Optima is truly 'set it and forget it' year round.
The Optima seems to be pretty intelligent about everything going on in the car, if the fan is blowing high enough that it is loud because you just started the car and it's working to get to set temp, and the phone rings, it will automatically lower the fan speed so you can hear the call better.

 

[gooffeyguy]

I picked up my Yukon with 113k miles on the clock and the only HVAC button that had any wear was the power button.
Mine seems to work OK, but not as nicely as the auto climate controls in my 2017 Kia Optima.
My Optima is truly 'set it and forget it' year round.
The Optima seems to be pretty intelligent about everything going on in the car, if the fan is blowing high enough that it is loud because you just started the car and it's working to get to set temp, and the phone rings, it will automatically lower the fan speed so you can hear the call better.

My 2012 Denali does that, lowers the HVAC blower speed when on a call.

Speaking of HVAC buttons, the 2011 Denali I had, had worn buttons and there were those stickers over them when I bought it in 2018. the 2012 that I bought a few months later after the 2011 was totaled had perfectly fine (like new) HVAC buttons and still does. I don't know if the control unit was ever replaced before I bought it from the Buick/GMC dealer or not. I'm thinking not because it was only ~6 years old when I bought it

 

[Doubeleive]

auto works fine here in cali for fall/winter, but once it warms up it's a no go, it can't keep the temperature cool in the summer even with a 100% perfectly working system unless you are on a long drive and it's had time to cool the interior first, I just leave it on manual 60 98% of the time
beside's it's nice to step into 60 degrees from 100 anytime otherwise

 

[89Suburban]

I think I finally found it brothers.

 

[89Suburban]

Have you replaced the sway bar links in the back?

I think I finally found it brothers.

tag rattle

 

[89Suburban]

Gd dman it

 

[Doubeleive]

Gd dman it

ZIP TIE IT, done

 

[iamdub]

ZIP TIE IT, done

NO!!! THE PROPER WAY IS TO RE-ROUTE THE CABLES OVER THE SWAY BAR!!!!11111!!!!ELEVEN!!!!