2015 YUKON NOISE IN CABIN

[Anon2015]

So, you know now that ANC is degraded. Next is to determine if one or both subs participate in ANR. If only one, disconnect that one and you're done and the tape and cotton balls can go away.

[Mortman]

This is the thread that was mentioned earlier with the wiring schematic for the sub. Looks like this guy clipped the blue/violet wire in the harness in the jack area (drivers rear) and rendered his ANC inop.

http://www.tahoeyukonforum.com/forum/showthread.php?t=68410

Edited January 12, 2015 by Mortman

[Mortman]

Anyone willing to clip their purple/blue wire and see if it resolves the buffeting issue?

[20Sierra14]

From this chart, the mics could actually just be clipped/unplugged from the AMP -- (stole the pic from the link above)

 

 

There is a "signal" and a "return".. I'm not familiar enough with which does what. I would only assume the signal would need to be "cut"...?

 

Secondly, the chart is saying the Violet/Dark Blue is the Crank Shaft sensor; meaning I have no idea why the guy would even use that cable to keep his sound system from buzzing..??

[Mortman]

He didn't have the schematic when he started. He was doing the ole tried and true trial and error method. He came upon one that worked. It seems that when any of the inputs are interrupted it shuts down the system entirely.

[20Sierra14]

double post..

Edited January 12, 2015 by 20Sierra14

[20Sierra14]

This kind of answered my own question --Sourced from "quaraong" on Cadillacforums.com:

 

 

"Sources have indicated that the Active Noise Cancellation (ANC) will interfere with the mono-amp and causes the “boom” on startup/door closing. It is required for the 10-spearker Bose system to disconnect the 3 ANC mics. Several people suggest cutting the wires at the mics location. I thought about this and decided not to because I didn’t want to disintegrate the door trim / weather strip / A-pillar / headliner. Another source suggested removal of these mics pins from the connector into the stock amp. I also thought about this but did not want to cut up the factory wires nor was I able to remove the pins, so no-go neither.....

 

I believe UQS means the 10-speakers and UQA means the base 7-speakers. According to the diagram (mine looks the same), the T3 X3 connector is dedicated to the ANC functions. I believe that “Low Speed GMLAN serial data” sends input to the amp, letting it know when the door is closed to activate the ANC functionality. “Crankshaft Position Sensor Replicated Signal” also appears to be an input of noise to be cancelled, acting the same role with the 3 cabin mics."

 

 

Sooo, from what I gather, the ANC can create a "booming" sound from modified sound system... This poster also stating that ANC can degraded/block the bass sound that the sound system is producing... So you guys who hate the Bose sound system could also benefit by turning off ANC! Haha!

[bamamike]

I was told today by the local service manager that GM had a fix message out and that the metal bows across the roof above the headliner were separating from the roof causing this booming sound. Wind over the roof driving down the road would make the bows reflect and going across any bumps would cause the feel/sound. The service statement also said this MAY or MAY NOT fix the SOUND/FEEL your experiencing?????

 

It's odd because I definitely get the sound/feel at low speeds 5mph over the slightest bumps (even concrete expansion joints) but when I hold 45-mph it sounds like a rotational noise but with the sound/feel of the boom on a rotation. The dealer said they have one other complaint and their vehicle is really loud at around 35-45 mph.

 

The GM recommended fix mentions that the stiffness of the rear end hitting bumps would cause this booming sound. It also mentioned tires out of round would cause the bows to flex(they've rotated and road forced balanced mine twice less than 5k miles) It almost sounds like the vibration of the drive train causing the sound. My first instinct says it's cheap tires (mine are Continental) but I'm not sure this is the problem.

 

The fix is to take the headliner out and place shims or insulation filler (ie foam) between the bows and the roof. The also mention in the fix that when the vehicle goes from 8 cyl to 4 cyl you get a muffled sound which I agree with but don't think it's all the problem because mine will do it with the tow haul engaged which keeps the vehicle out of 4 cyl over drive.

 

I think it's more than one issue and all these 2015 sound proofing or dampening features have amped up this internal sound/feel. I have no knowledge of the sound system and how it works or plays a part in this problem.

 

I can't drive the car under these circumstances and not sure I want the headliner ripped out. I was assured that they snap in and use no glue etc which was required with the old liners???? You will literally go crazy driving this car down the road. I wished I would have found this site before I bought the vehicle. I hope this solves the problem because we will not keep this vehicle. We recognized this issue the first time we test drove the vehicle but was told by the salesman it was flat spotted cold tires which made since at the time.

 

They are going to get our car soon and keep it for a test drive over several days. I told them not to do anything until they check with me, I will keep you guys posted.

[bamamike]

Oh yea I have a Yukon XL not sure I even have (anc) but mine does have the bose stereo system.

[The Zip]

bamamike - these fix recommendations is what GM was trying back in September last year, look at some of the early pages (1-5), didn't work then. Or, this could be an updated fix message, ask the question

[Wrench589]

Based on the pinout for the X1 connector at the amplifier, pin 1 is the "Left/rear subwoofer speaker (+)" and pin 5 is the "Right subwoofer speaker (-)". No other mention of subwoofer, so no corresponding (-) and (+) for these, so I believe there is only a single subwoofer since you need and + and - for each speaker (each other speaker shows a + and - for each). Wouldn't be the first time I've seen a manufacturer's documentation with a typo in it! And I've worked with all the multinationals, from General Electric, to Siemens, to Caterpillar, etc, etc, etc.

 

As well, there is a full list of each and every component in the electrical system and it's location, right down to the microphones, the door switches, everything. It only lists one subwoofer, and says that it is location under the dash, in front of the floor console. Pretty common place in most trucks and truck based suv's. So, no surprise.

 

Also, I would think that the crankshaft position sensor signal is being used for the engine noise cancellation that Bose talks about - Active Sound Management, I believe. As I understand it, the Bose system is pre-programmed with sound based on engine speed, and outputs this sound via the speakers to cancel known engine sounds. This approach is also used in some cars to give the engine a more throaty sound, since some modern engines/exhausts have been made too quiet! Anyway, not sure what effect disconnecting that sensor will do.

 

I'm wondering about trying to pop the microphone grill off and getting at the microphone connectors themselves. Would be the easiest if the grills pop off. My luck, gotta take the headliner off to access from behind!

 

If the dealer ends up taking my headliner off, I will insist that they Dynamat the entire roof. Either that, or spray foam the shit out of it. That stuff makes thin-tin stiff as hell. Of course, a disaster if any gets on the interior. And god forbid you gotta go back in there to make any other changes!

 

I was hesitant to have them remove the headliner, but I'm at the point where they can take the whole fricken thing apart! Can't be any worse then it already is!

 

One other thing I picked up on - someone commented that then new headliner just snaps in, not like the old ones that were glued in. REALLY? So, the headline can just flop around up there? And make booming sounds?

 

Just saying.....

[Wrench589]

One more thing, if you look on the plastic connector, you should see the manufacturer and model of it. Go on line and look up the tool needed to remove the pins without damaging anything. Get the tool and use it to pull whichever pin you are testing. Better then cutting wires. I've done this on other vehicles and may have to spend a few bucks but infinitely better then cutting wire!

[Anon2015]

Good catch, Wrench ... I totally flew by that.

[jasondenali15]

I was told today by the local service manager that GM had a fix message out and that the metal bows across the roof above the headliner were separating from the roof causing this booming sound. Wind over the roof driving down the road would make the bows reflect and going across any bumps would cause the feel/sound. The service statement also said this MAY or MAY NOT fix the SOUND/FEEL your experiencing?????

 

It's odd because I definitely get the sound/feel at low speeds 5mph over the slightest bumps (even concrete expansion joints) but when I hold 45-mph it sounds like a rotational noise but with the sound/feel of the boom on a rotation. The dealer said they have one other complaint and their vehicle is really loud at around 35-45 mph.

 

The GM recommended fix mentions that the stiffness of the rear end hitting bumps would cause this booming sound. It also mentioned tires out of round would cause the bows to flex(they've rotated and road forced balanced mine twice less than 5k miles) It almost sounds like the vibration of the drive train causing the sound. My first instinct says it's cheap tires (mine are Continental) but I'm not sure this is the problem.

 

The fix is to take the headliner out and place shims or insulation filler (ie foam) between the bows and the roof. The also mention in the fix that when the vehicle goes from 8 cyl to 4 cyl you get a muffled sound which I agree with but don't think it's all the problem because mine will do it with the tow haul engaged which keeps the vehicle out of 4 cyl over drive.

 

I think it's more than one issue and all these 2015 sound proofing or dampening features have amped up this internal sound/feel. I have no knowledge of the sound system and how it works or plays a part in this problem.

 

I can't drive the car under these circumstances and not sure I want the headliner ripped out. I was assured that they snap in and use no glue etc which was required with the old liners???? You will literally go crazy driving this car down the road. I wished I would have found this site before I bought the vehicle. I hope this solves the problem because we will not keep this vehicle. We recognized this issue the first time we test drove the vehicle but was told by the salesman it was flat spotted cold tires which made since at the time.

 

They are going to get our car soon and keep it for a test drive over several days. I told them not to do anything until they check with me, I will keep you guys posted.

Don't do it! They did it to my first one and it did not resolve a thing...I don't think it worked for anyone.

[The Zip]

20sierra14 – in reference to post #480, you get an “A” for intent and purpose, got it. However, you get an “D” for effort. You probably could have done a better tape job on your 70K truck.

 

The pictures look like you placed the cotton and tape over the mics. Here are a few questions for you; 1) Does the mic cover come off? If so, is there a stock number? 2) If the cover comes off, is there space between the mic components and cover? 3) Does the mic come out of the housing? 4) If the mic comes out of the housing, is there a connection? 5) If the mic cover comes off, have you tried driving with it off?

 

I would try this, but my mics are covered under the headliner. Also the mic covered over the drivers’ sunvisor is for Bluetooth, covering this one may complicate vehicle voice commands in addition to muffling your external transmission.

Edited January 14, 2015 by The Zip