2015 YUKON NOISE IN CABIN

20Sierra14 · January 17, 2015

Well, based on what my wife tells me, I can corroborate 20Sierra14's result. That make two of us, buddy!

Awesome! I really hope this is the solution to everybody's "HEADACHES".

Be careful, though, as the ANC seems to "re-learn" the cabin's noise conditions and then adapts, which could bring the noise back.. In other words, you may need more "suppression" than a towel

Wrench589 · January 17, 2015

Awesome! I really hope this is the solution to everybody's "HEADACHES".

Be careful, though, as the ANC seems to "re-learn" the cabin's noise conditions and then adapts, which could bring the noise back.. In other words, you may need more "suppression" than a towel

Interesting you mention that it "adapts". I was talking about that on one of my earlier posts. As I previously mentioned, engine control systems have had adaptive values for many years now, so no reason to think that they wouldn't incorporate the same approach in the sound control system. Would explain why someone posted that they pulled the fuse and then put it back in and the system seemed better for a while, then went bad again (once the system re-learned it's bad manners!).

Boy, it would be helpful to know exactly how the system functions. Hard to diagnose it when it's a mystery!

Anon2015 · January 17, 2015

Just a couple of points -- (four actually)

1. The microphones would not have 'brains', clearly; however, it could be possible that the failure of one microphone would shut, or fault, the ANC system. That does not appear to be the case.

2. If there is a microphone behind the headliner and that headliner moves (fairly quickly), that would create a false signal to the ANC system. Microphones do not measure sound ... they measure changes in air pressure which is exactly what a 'flapping' headliner would do.

3. It appears the only 'success' has been to damp the changes in air pressure at all microphone positions.

4. With the pin extraction tool for the connector, one could disconnect all microphones noted as 'noise compensation' and see what happens. If the result is the same as the tape and cotton ball exercise, then there is your fix.

Edited January 17, 2015 by Anon2015

Anon2015 · January 17, 2015

"Adapts"

I suppose that could be possible but I'd question that in general ... what does it 'adapt' to and when does it know conditions have changed and the adaption is no longer of value? Adaption would also mean it is not compensating for the addition or subtraction of salt water bags as they are added and subtracted from the cabin. Salt Water Bags = humans and dogs (great low frequency absorbers).

TOBTEK · January 17, 2015

So after a conversation with the area GM area engineer on Thursday, we agreed to go get the Escalade out of the service dept. Where it's been for almost a month now. Might as well have my wife drive her Christmas present since we are paying the payment and insurance. They are putting new re-valved shocks on it. He said there are several complaints of the very stiff ride. I think the Std shocks are complete junk! There is no rebound control, the dampening is way too hard. The vehicle is a total pogo stick. Our " I " model DOES HAVE the exposed mic's above the grab handles and the one in the middle rear. Not certain on how to remove the grills, and don't want to damage them. I would assume if I cut a few pieces of duct tape and placed it over the grills, most of the sound would be reduced ??

Didn't notice the V8 to V4 mode the first few days we had it. Now yesterday was driving slow through neighborhoods looking at homes. Did notice a large rumbling into V4 mode. It sounds and feels like when a vehicle is running out of gas. I'd be willing to override the V4 all together and lower speeds. It's pretty annoying.

Picked my daughters up from school, with in minutes one said " my ears are plugged". I'm so agitated we bought these vehicles for the enjoyment of our families, and now we have to deal with this type of situation. I wish there was another SUV that fit our requirements! I'd like to give this OVERPRICED thing back, and stop trying to fix these problems for the manufacture. And made to feel I'm the jerk to asking for these issues to be corrected.

Wrench589 · January 17, 2015

"Adapts"

I suppose that could be possible but I'd question that in general ... what does it 'adapt' to and when does it know conditions have changed and the adaption is no longer of value? Adaption would also mean it is not compensating for the addition or subtraction of salt water bags as they are added and subtracted from the cabin. Salt Water Bags = humans and dogs (great low frequency absorbers).

LOL! Salt water bags. Love it.

I hear you. Pure speculation on my part, but adaptation could be modelled after what is done with engine control systems. For example, most modern engine control systems will have some kind of fuel trim that will bias the fuel map based on what the O2 sensor closed loop feedback has been saying, in essence creating a feed-forward component. As the conditions dictate, the trim value will evolve over time to keep with the feedback. This results in relying less on the feedback portion to get exact air/fuel ratio control, because feedback can, of coarse, be tricky to get what you want. Make the control loop too slow to respond and the results can't track transients. Make it too fast responding, and it overshoots and never becomes stable.

Anyway, who knows what's in the Bose!

Wrench589 · January 17, 2015

Tobtek, very interesting about different shocks. I totally feel something in the suspension is too stiff. Every little bump or pebble seems to sound up through the chassis. I think that makes the ANC response worse. In fact, I have driven stretch or road close to our place that is slightly rougher pavement that then has a super-smooth stretch, and when the vehicle passes from the rough to the smooth the buffeting pretty much disappears. What does that tell you!

I feel your pain, man. If there was another option, I'd be pushing that way. Since there really isn't, need to stay the course, I guess. But like you said, it's extremely frustrating to have to put in this kind of effort just to be made feel like there really isn't anything wrong and I'm being too fussy. Hmmmm. Not the way it's supposed to be.

But, I guess it could be worse. Imagine we lived in a part of the world where things are pretty rotten these days. If this is the worst thing I have to deal with in my life, I think I'll be OK!

Cheers!

Wrench589 · January 18, 2015

Bad news.... Wife drive it today and came home and said "it's back, but not as bad". I took it for a drive and at first thought it was quite a bit better but could still hear a faint version of it but no actual pressure sensation. I was encouraged. By the time I got home,mid have to say I'm not sure it isn't every bit the same as before. Of course without quantitative measurements to compare, it's really tough to assign how bad it is. Bottom line - I can still hear it.

I'm going to look at disconnecting the microphones from the plug at the amplifier. With some plugs, you don't need the proper tool, so maybe I'll get lucky. Plus, I might try pulling the amp fuse again and seeing what happens. Starting to have second thoughts on whether the ANC is the problem or not.

20Sierra14 · January 18, 2015

Com'on fellas - Pull the grilles off and stuff the cotton balls in there! Don't be afraid of messing up a $4 grille! I went from horrible headaches/ear pressure on New Year's Eve to having ZERO issues for weeks now! I'm actually back to loving our Denali! Fit, finish and ride are all on par as to what I would assume GM wanted us to have -- minus the horrible Bose sound/ANC system.

The stiffness of the truck, to me, doesn't have much correlation to the ear pressure -- I think that's another totally different problem. The "buffeting" certainly can correlate to a noise being detected via the drive-train that *could* create a "false" tone in the cabin that would create the sensation of the buffeting and cause ear pressure.

Solution?? Go to the "ears" of the system creating it.

The Zip · January 18, 2015

All - my recommendations are for buffeting only, this is all I was working on since my truck does not exibit anything associated with this thread. However, folks on this thread could benefit by my research from my particular issue. Just as an informational, I purchased my truck in Mar '14. Since that time I have researched Plans, Manuals, Instructions from associated manufacturers (GM/Bose/XM/Auto Part stores, etc.) consisting of over 3000 pages. So at this point I have connected all the dots but I can mitigate my issue (don't tune in specific XM channels) without going any further for personal benefit. Although I wish I had access to my mics. At this point, I doubt the experts have the collective data associated with this thread, so kudos.

20sierra - Although there is a possibility these are two separate issues, don't totally eliminate the ANC correlation with stiffness in the suspension, data I've read don't support that assessment. Your cottonball concept is sound, it achieves the same results of what I would do except without the cottonballs.

tobtek - When you take back your truck to the dealer, see if they can close the deal and disconnect the remaining 2 mics. If not, ask them to go to the audio amp and disconnect pins 4, 5, 6 for signal and pins 12, 13, 14 for return. The mics and pins are ANC associated.

wrench589 - if you are going to pull pins, it's better to be good cause I don't think you will be lucky (I've seen the pin configuration), so here is some help. Pin extraction tool; GM Service Tool J-38125-215A. If you can't get that tool, a 0.8mm flathead screwdriver will work just as well. Pull same pins as identified above.

20Sierra14 · January 18, 2015

Forget the tool.. I'm almost to the point to where I'll just cut the wires of the signal/return... Hell, I have masking tap plastered all over the truck now, why not just strip and solider the wires back if needed -- THEN I could take down the cotton balls and tape! hahaha!

The Zip · January 18, 2015

20sierra14 - lol, there goes your warranty. Data doesn't support that recommendation. Although I will come clean and tell you this is one of the mitigation measures.

Edited January 18, 2015 by The Zip

The Zip · January 18, 2015

wrench589 - I think I saw the same pin configuration at the fuse along with the amp. Also, my amp is secured by a round nut, you may need a special tool to pull the box or maybe a needle-nose will work

Apologies on this post, the round nut is applicable to the rear fuse box, nothing to do with the amp

Edited January 18, 2015 by The Zip

The Zip · January 18, 2015

20sierra14 - drooling to get to my mics, I used my Bluetooth grille as a test dummy a few months back. If you must use tape, clear packing tape is stickier and provide better aesthetics.

The Zip · January 18, 2015

20sierra14 - did you replace the grille under the tape or did you place the tape over the cotton. The better option is to replace the grille, then cover with the tape.