What's Wrong With Your Yukon/Tahoe Today? ...And How Long Has This Been Happening?

[ProfeZZor X]

In the last few months, my Yukon had a software update. Since then, little things have been happening like random chimes, random icon displays, and so on. But, it's not so much that it's been a major problem... Until now. Now I can't unlock my doors using the door handle button. I have to manually unlock it using the key fob. I'm wondering if it has to do with my key fob battery, and that it won't give off a signal to the vehicle if the battery is low. I could be wrong, but has this happened to anyone?

 

[WalleyeMikeIII]

iPhone autoconnect using Wireless CarPlay never works at startup, was a periodic occurance, but after iPhone update to iOS 17, its a sure thing, 95% of the time it will not autoconnect at startup.

Workaround is:
On Infotainment system:
-Hit Phone Icon
-Select Manage Phones
-Disconnect the iPhone
-Wait for the phone ot disconnect and until CarPlay icon appears in the phone icon on the screen
-Touch the icon, about 5s later, it connects.

 

[B-train]

On my 2008 Denali, I've had a rough idle on startup and lower brake pedal assist for a number of months now. Coupled with a bit lower than expected MPG. I figured I had a vacuum leak of some sort. Also, the fuel trims seemed to be off a little bit compared to what I've seen on this site from others - I attributed this to my running of E85 blends to find the sweet spot so didn't really think much on it.

Last night I decided to have some homemade wine and give the old girl a look-see. All vacuum lines looked good, intake bolts tight, etc. While poking around, I noticed map sensor wasn't tight in is hole. I removed it to find the ribbed o-ring all flattened out from 182k miles of use.

I fluffed up the ribs as best I could, then coated it with a healthy dose of grease and plopped it back in as a test. Fired up the truck and it idled as smooth as glass. Took a test drive and noticed smoother running, better braking, and fuel trims in the 0-1 range.

It was a shot in the dark, but seems to have helped. Time will tell on a couple more uses, but so far, so good. I will get a new GM sensor after the testing is done. It's amazing what affect a small vacuum leak can have.

 

[cmatthews77]

2021 Tahoe and the FM radio doesn’t work initially. The workaround is I have to hit the home button, audio, then go to AM radio and then back to FM radio and it’ll work. If you go to FM first it won’t play.

 

[KMeloney]

2021 Tahoe and the FM radio doesn’t work initially. The workaround is I have to hit the home button, audio, then go to AM radio and then back to FM radio and it’ll work. If you go to FM first it won’t play.

Is your iphone auto-connecting when you get in the truck? I've found that if it does, and your phone is trying to play audio/video on it (even if it's on a site that has a pop-up video ad trying to play), then you get kicked out of AM/FM (not sure about XM), and you have to then toggle between frequencies/bands and back to where you were. Annoying, yes, but...

Is that what's happening in your situation, or does it happen even when your iphone doesn't auto-connect/when Carplay is not connected?

 

[cmatthews77]

Is your iphone auto-connecting when you get in the truck? I've found that if it does, and your phone is trying to play audio/video on it (even if it's on a site that has a pop-up video ad trying to play), then you get kicked out of AM/FM (not sure about XM), and you have to then toggle between frequencies/bands and back to where you were. Annoying, yes, but...

Is that what's happening in your situation, or does it happen even when your iphone doesn't auto-connect/when Carplay is not connected?

Well I do sometimes get kicked off or disconnected from radio if the vehicle thinks I’m trying to play phone and I’m connected.

However, this is a different issue and happens whether I have my phone connected or not. The FM tuner won’t engage unless I first go to AM and then back to FM. It’s very annoying

 

[ProfeZZor X]

Took my Yukon to the Thousand Oaks GMC dealership Saturday morning for an oil change, and I guess it turned out being more serious than that. They found oil condensation on the pan, but no leaking. They replaced the gasket, and had to allow it to seal properly for a few days, which they were more than generous to provide me with a loaner. I also had some electrical issues which they promptly fixed, and also installed a brand new heated steering wheel that was due to me because of supply chain issues a few years ago. Because of the new steering wheel, I got a free wheel alignment, so that was a plus. They even went so far as to wash and fully detail my Yukon before I picked it up. Hell, it looked better than if I had washed and detailed it myself.

In all, I had a fantastic experience with them, and that's why I think it's worth the 100 mile drive to get there.

 

[Punteh]

Tonight on my way home from work my CEL came on after some shuttering. When I got home I connected my code reader and I got the code P0300 Random Misfire. My Yukon Denali has 6400km on it. Great. Are you not able to clear codes on these vehicles? Everytime I tried with my code reader it would lose connection with the vehicle. So the code is still there. Obviously being Friday night I won't be able to get into the dealer until at least Monday morning to look into it.

Any recommendations with this code for the weekend? Is it ok to drive or would that possibly make things worse?

 

[WalleyeMikeIII]

You could hit the onstar button and get the remote diagnosis will probably reveal more specific codes

 

[Punteh]

You could hit the onstar button and get the remote diagnosis will probably reveal more specific codes

Do you know if the CEL will prevent remote start from working? Today it's not starting with the remote or through the MyGMC app. It's starting fine using the start button in the vehicle

 

[StephenPT]

Do you know if the CEL will prevent remote start from working? Today it's not starting with the remote or through the MyGMC app. It's starting fine using the start button in the vehicle

Pending codes will not allow remote start.

 

[Punteh]

Tonight on my way home from work my CEL came on after some shuttering. When I got home I connected my code reader and I got the code P0300 Random Misfire. My Yukon Denali has 6400km on it. Great. Are you not able to clear codes on these vehicles? Everytime I tried with my code reader it would lose connection with the vehicle. So the code is still there. Obviously being Friday night I won't be able to get into the dealer until at least Monday morning to look into it.

Any recommendations with this code for the weekend? Is it ok to drive or would that possibly make things worse?

I’ve been driving my Yukon sparingly since the CEL came on and didn’t drive it at all yesterday. About an hour ago when I drove it I noticed that the light was gone. I have an appointment at the dealership on Friday but now there’s no light for them to check. Although I already told them what the code was. Is there anything in the computer that they can check or if I bring it in without the light on are they going to say there’s nothing they can do? It’s been running fine the last few times I’ve driven it so it really was a random misfire that caused the light to come on in the first place.

Another side note, after months of the speed limit sign on the HUD being blank when I drove it today the speed limit was displayed again. This vehicle does some random things

 

[StephenPT]

I’ve been driving my Yukon sparingly since the CEL came on and didn’t drive it at all yesterday. About an hour ago when I drove it I noticed that the light was gone. I have an appointment at the dealership on Friday but now there’s no light for them to check. Although I already told them what the code was. Is there anything in the computer that they can check or if I bring it in without the light on are they going to say there’s nothing they can do? It’s been running fine the last few times I’ve driven it so it really was a random misfire that caused the light to come on in the first place.

Another side note, after months of the speed limit sign on the HUD being blank when I drove it today the speed limit was displayed again. This vehicle does some random things

Software glitches are part of the "experience" at this point. There is so much software/hardware on these vehicles that as they fix issues in one place, new issues come up in other places. Also, with the amount of modules/features all booting up and communicating, there's bound to be a time or two where things don't boot up correctly. After about 10 months into owning my Yukon I had a drive cycle where the backup camera didn't work. Next time I started it, no issues and hasn't happened since.

As far as the CEL - all codes are stored in the system with an ID of which drive cycle it occurred. After ~40 drive cycles, the system will erase the code. When the dealership hooks up to it, they can see it in the list of stored DTCs. Active DTCs are also shown and if you have a check engine light on at that moment, they will be in that list.

Every dealership is different. Some will say "Its not an active code, check engine light is gone - come back when it is an issue." Also, from what you said about it now running fine, they will likely say you got a "bad tank of gas" or something along those lines. You can still keep your appointment, but don't be surprised if it ends up being a waste of time.

 

[SCiesie154]

2022 yukon sle ....I just noticed my doors do not shut tightly. There is about an eigth of an inch of play when i push in on the doors after they are shut.No rattlles due to the amout of weatherstrip. Wind noise has increased a little since new in may of 2022

 

[KMeloney]

In the 2 months I've owned my Yukon AT4, I occasionally hear a "thud" behind the driver's seat, as if a bowling ball hit somewhere behind me when I'm driving alone. Nothing moves around back there, it only happens once a day, and I don't feel any vibration in the floor when it does happen. I thought it might be the sliding rear seat, but it takes some muscle to slide them back and forth because of how stiff they are on the sliding track. And my kids never adjust the seats either. Very strange.

Did you ever figure out what this clunk is/was? I felt what I think is the same thing making a tight-ish right turn through an intersection that had a slight drop-off to it. Felt just like you describe here, like a bowling ball rolled into something insulated (no harsh impact sound -- but a muffled "clunk" feel and maybe sound)...

 

[Jay P Wy]

Did you ever figure out what this clunk is/was? I felt what I think is the same thing making a tight-ish right turn through an intersection that had a slight drop-off to it. Felt just like you describe here, like a bowling ball rolled into something insulated (no harsh impact sound -- but a muffled "clunk" feel and maybe sound)...

No issues with our Tahoe, but had an issue like this in my 21 Silverado. It turned out the spare tire wasn't tight against the frame and was moving around at times. Tahoe/Yukons have the same type of spare tire carrier that the pickups have. I haven't looked for the access to the winch to raise/lower the spare on the Tahoe yet but it has to be near the hitch area or visible when the hatch is open.

 

[ProfeZZor X]

No issues with our Tahoe, but had an issue like this in my 21 Silverado. It turned out the spare tire wasn't tight against the frame and was moving around at times. Tahoe/Yukons have the same type of spare tire carrier that the pickups have. I haven't looked for the access to the winch to raise/lower the spare on the Tahoe yet but it has to be near the hitch area or visible when the hatch is open.

I'll have to check that out to see if my spare is loose. The only thing about that is that it doesn't repeatedly do it. It happens only once while driving, and the sound appears to be coming directly from the rear passenger seat behind the driver.

The other issue I've experienced is the "ghostly" mechanical automation behind the dashboard on the driver side, after I've shut the vehicle off. It usually takes a few minutes, but there's something mechanical going on behind the dash, as if a "transformer" is reforming into his robot form. That sound is more frequent than the one mentioned above, but I'm guessing that sound has to do with the power mechanisms equipped in the vehicle... Like power steering or power brakes readjusting into a neutral position until the vehicle is back in use.

 

[mountie]

I'll have to check that out to see if my spare is loose. The only thing about that is that it doesn't repeatedly do it. It happens only once while driving, and the sound appears to be coming directly from the rear passenger seat behind the driver.

The other issue I've experienced is the "ghostly" mechanical automation behind the dashboard on the driver side, after I've shut the vehicle off. It usually takes a few minutes, but there's something mechanical going on behind the dash, as if a "transformer" is reforming into his robot form. That sound is more frequent than the one mentioned above, but I'm guessing that sound has to do with the power mechanisms equipped in the vehicle... Like power steering or power brakes readjusting into a neutral position until the vehicle is back in use.

I had a bad HVAC actuator that made a weird noise after turning off the key....

 

[WalleyeMikeIII]

I'll have to check that out to see if my spare is loose. The only thing about that is that it doesn't repeatedly do it. It happens only once while driving, and the sound appears to be coming directly from the rear passenger seat behind the driver.

The other issue I've experienced is the "ghostly" mechanical automation behind the dashboard on the driver side, after I've shut the vehicle off. It usually takes a few minutes, but there's something mechanical going on behind the dash, as if a "transformer" is reforming into his robot form. That sound is more frequent than the one mentioned above, but I'm guessing that sound has to do with the power mechanisms equipped in the vehicle... Like power steering or power brakes readjusting into a neutral position until the vehicle is back in use.

Normal part of operation...

 

[mountie]

Normal part of operation...
View attachment 422897

Well, someone did their homework !!