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Buzzing Sound Under Dash at Startup - 2021 1500

741 Views 6 Replies 4 Participants Last post by  Nicolasmoyer
Hey, I just picked up a 2021 Silverado Trail Boss LT, and I'm wondering a couple things about it. The first curious thing is a slight buzzing sound coming from somewhere under the dash right at startup. It kind of sounds like a CD player when it pulls in a CD, but there's obviously no CD player in it. It happens right when I push the start button, in the brief moment before the starter engages. It doesn't sound like something's wrong; I'm just curious what creates that sound.

Bonus questions:
  1. This truck has lots of options, but it doesn't have memory seats. Is there some reason why this is? I was thinking it might've been one of those chip shortage issues, but there are no provisions at all for memory seats/mirrors.
  2. Another option that I find odd that it doesn't have is the parking assist/backup sensors. Does it seem odd that this truck wouldn't have them, or is that typical for this vintage? Most of my previous recent other Chevy trucks have had them - pickup, Tahoe, and Avalanche, as did all of the SUVs that my wife has had in the last 10+ years. I'll look for a thread on this, but has anyone ever installed aftermarket ones successfully, and was it worthwhile?
Thanks in advance, and please see my post about tire recommendations for a Trail Boss!
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I checked the option groups; Hope this helps answer your questions.
They are extra cost options and not standard equipent. If you bought the truck off the lot then what you got is how the dealer ordering it configured it. Lots of times options are on constraint meaning limited supply and dealers will omit them from stock orders so the vehicle build is not delayed.

PQB Safety Package, includes (UD5) Front and Rear Park Assist, (UKC) Lane Change Alert with Side Blind Zone Alert and (UFG) Rear Cross Traffic Alert

The only way to get heated seats in a Trail Boss is to also have this option package. Check your window sticker for the extra cost item

PCH Convenience Package with Bucket Seats, includes (A50) bucket seats, (D07) center console, (CJ2) dual-zone automatic climate control, (A2X) 10-way power driver seat including power lumbar, (KA1) heated driver and passenger seats, (KI3) heated steering wheel and (N37) manual tilt/telescoping steering column; Crew Cab models include (R7O) Cloth Rear Seat with Storage Package
1 - Leather seats require (CXH) Leather Package and includes (SNR) Up-level Rear Seat with Storage Package.

Source - GM Ordering Guide
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Thanks for the detail. I do have all of the PCH Convenience Package items; I was just surprised it wouldn't have the memory seats and park assist along with those. It makes sense that they didn't order those two options if they were avoiding the chip shortage issues, I suppose. I'm thinking about going with the Katzkin leather seats - I have buddy who does upholstery, and he says that's a nice option. Or maybe I'll stick with the cloth for a while - it's been a long time since I had a cloth interior. The last one was in a 2000 2500 crew cab that had the velour texture, and as long as I have heated seats (I'm in MN) and steering wheel, I'm happy for now.
I have never seen cloth seats with heated or cooled feature. Reason, cloth does not feel cold as leather does so those features have limited practicality.

KA1 Seating, heated driver and front outboard passenger
KQV Seats, ventilated driver and front passenger (not available on Trail Boss. limited to LTZ & High Country)

Keep in mind, Trail Boss models are primarily an off-road and some creature comforts are not deemed a desirable feature.
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Bump. I'm curious about the first part of my question—no takers yet!

Besides the buzzing sound that comes from under the dash at startup, there is also a whole mess of noises that happen maybe a minute after shutting it off: a series of clicks, etc. I don't think it is anything to be concerned about, I'm just wondering what all those sounds are. I've owned at least 10 GM vehicles since 2000 and haven't had any that make all of these sounds. Curiosity is getting the best of me!

Thanks in advance,
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