6.2L Active Noise Cancellation

CounterMeasure · April 21, 2015

According to GMC and Chevy's website, the 6.2L comes with active noise cancellation. I've had my Denali for a few months now, and in that time, I've never noticed anything that tells me there is such a feature working. Usually with true ANC headphones, I am pretty sensitive to the dead silence they can create. Went on 550 mile road trip this weekend, and had various degrees of wind and road noise on the drive, with nothing seeming to happen to fix it. At this point, I don't think its working or installed. I have the three mic grilles in the cab, but haven't pulled one to see what's back there. I don't see anything in the HMI's menus to even tell me about it, much less adjust it. Don't see anything obvious in the hidden system menu either.

Anyone notice theirs working or any options for it? Maybe I got the wrong programming at the factory?

ConnRadd · April 21, 2015

Following...

fondupot · April 21, 2015

This article describes how the ANC works, its describing it on an equinox, but you get the idea. You aren't going to notice it at higher RPM's....also it's designed so you don't notice it.

http://www.gizmag.com/noise-cancellation-improves-fuel-efficiency/19826/

Edited April 21, 2015 by fondupot

The Zip · April 21, 2015

Countermeasure - I've read posts from folks on the SUV forum equate ANC to the number of grilles. But through my research on another thread, ANC is based on the Bose speaker system installed in the vehicle versus the number of grilles. The 2015 Sierra 6.2 comes equipped with either the UQA or UQG Bose speaker systems. UQA w/o ANC, UQG w ANC. You would have to find your specific speaker system RPO Code to know whether or not you have ANC.

high country · April 21, 2015

I maybe wrong but I don't think the ANC works on any noises except those made by the engine.

The main components of the Active Noise Cancellation system are:

3 microphones in the vehicle headliner.
A discrete engine speed (RPM) signal from the engine control module to the amplifier
Active Noise Cancellation electronics and software integrated into the audio amplifier
The vehicle speaker system, connected to the amplifier, to output the desired cancellation frequencies

The Active Noise Cancellation system is operational under the following conditions:

The amplifier has passed all self diagnostic checks
All doors are closed
Battery voltage is between 9.5 V and 16 V
The vehicle cabin temperature is less than 140°F (60°C)
Engine speed is between 550 and 3000 RPM

The Active Noise Cancellation system is a method used to reduce the perception of certain undesirable sounds generated by the engine into the vehicle cabin. The systems uses microphone and engine speed signals, software integrated into the amplifier, and the vehicle speakers to determine and generate the correct frequencies needed to achieve the desired reduction.

Three microphones are located in the headliner to monitor noise/sounds in the vehicle cabin, and are directly connected to the amplifier. The amplifier also receives a discrete engine speed (RPM) signal from the engine control module. The amplifier processes these inputs to determine the frequency of the undesirable sound. The amplifier then calculates the appropriate cancellation frequency and outputs a cancellation signal (audio tone) to the vehicle speakers to reduce the perception of undesirable sounds by the vehicle occupants so the vehicle cabin appears quieter and without vibration.

high country · April 21, 2015

XL7

Frequencies Rating – 315 MHZ, Long Distance

XL8

Frequencies Rating – 433 MHZ

2016 Sierra Owner · April 21, 2015

I maybe wrong but I don't think the ANC works on any noises except those made by the engine.

The main components of the Active Noise Cancellation system are:

3 microphones in the vehicle headliner.

A discrete engine speed (RPM) signal from the engine control module to the amplifier

Active Noise Cancellation electronics and software integrated into the audio amplifier

The vehicle speaker system, connected to the amplifier, to output the desired cancellation frequencies

The Active Noise Cancellation system is operational under the following conditions:

The amplifier has passed all self diagnostic checks

All doors are closed

Battery voltage is between 9.5 V and 16 V

The vehicle cabin temperature is less than 140°F (60°C)

Engine speed is between 550 and 3000 RPM

The Active Noise Cancellation system is a method used to reduce the perception of certain undesirable sounds generated by the engine into the vehicle cabin. The systems uses microphone and engine speed signals, software integrated into the amplifier, and the vehicle speakers to determine and generate the correct frequencies needed to achieve the desired reduction.

Three microphones are located in the headliner to monitor noise/sounds in the vehicle cabin, and are directly connected to the amplifier. The amplifier also receives a discrete engine speed (RPM) signal from the engine control module. The amplifier processes these inputs to determine the frequency of the undesirable sound. The amplifier then calculates the appropriate cancellation frequency and outputs a cancellation signal (audio tone) to the vehicle speakers to reduce the perception of undesirable sounds by the vehicle occupants so the vehicle cabin appears quieter and without vibration.

Exactly!! The ANC in these trucks is for the engine noises. Not every noise in or outside the truck unfortunately.

Edited April 21, 2015 by Blue Sierra Owner

Nickshu · April 21, 2015

XL7

Frequencies Rating – 315 MHZ, Long Distance

XL8

Frequencies Rating – 433 MHZ

Just looked, my '14 High Country 6.2L has XL7 on the RPO code sticker. Cool to read this thread and find out a nice feature I didn't even know that it had!

high country · April 21, 2015

Nice, mine has the same rpo as yours I understand why they call it the long distance as the truck just begs to be driven on road trips.

CounterMeasure · April 21, 2015

Ah, so they are using ANC only for low RPM groan. That's nifty and sneaky at the same time. When I went to order my truck, I was told that ANC was an option on any '14 and it was described as full-blown noise cancellation, but now only included on '15s with the 6.2L. Since I was doing a factory order to get the 6.2L anyway, I thought I was getting the full feature for "free". Instead, it looks like they are using it only to mask the engine in certain RPMs. I'll go look at the RPO sticker a little later and see what code it shows.

Thanks everyone for their time and info to educate me on this.

DanY · April 21, 2015

My '15 High Country with 6.2L shows RPO code of UQA. I take it this means not ANC system.

The RPO list shows UQA as "Bose Sound with 6 speaker system" and UQG as "6-speaker audio

system"

BTW what is the XL7 and XL8 codes you guys are talking about? Mine has XL7 but no mention

of this code in the RPO list that I have.

redwngr · April 21, 2015

UQA Bose Sound with 6 speaker system, (7 speaker system including subwoofer when ordered with bucket seats)

1 - Included in (GAT) All-Terrain Package, (PDB) SLT Crew Cab Value Package or (PDC) Texas SLT Crew Cab Value Package. Required when (L86) 6.2L EcoTec3 V8 engine and (AN3) bucket seat are ordered and includes (NKC) noise control system.

UQG 6-speaker audio system, included with (NKC) Active Noise Cancellation

1 - Not available with (UQA) Bose Sound speakers. Included and only available with (L86) 6.2L V8 EcoTec3 engine and (B3F) bench seat.

NKC Noise control system, active noise cancellation

1 - Included and only available with (L86) 6.2L EcoTec3 V8 engine.

UQA is a free flow RPO code, UQG and NKC are 'ref only rpo code'

mikemaat · July 21, 2016

Countermeasure - I've read posts from folks on the SUV forum equate ANC to the number of grilles. But through my research on another thread, ANC is based on the Bose speaker system installed in the vehicle versus the number of grilles. The 2015 Sierra 6.2 comes equipped with either the UQA or UQG Bose speaker systems. UQA w/o ANC, UQG w ANC. You would have to find your specific speaker system RPO Code to know whether or not you have ANC.

For future readers, this is incorrect. UQA is the Bose system, but NKC is noise cancelling. I have a 6.2 All Terrain with both Bose and Active Noise Cancellation.

mikemaat · July 21, 2016

XL7

Frequencies Rating 315 MHZ, Long Distance

XL8

Frequencies Rating 433 MHZ

These are keyless entry/remote start frequencies. Not sure why they are mentioned in this thread.

Dnt · July 22, 2016

2016 Denali Got a NKC rpo code so I guess it is on there but cannot tell if it works or not. I wonder if it can be turned on and off like on the center screen thing? Could test it that way I guess.