I had a '19 LTZ 6.2 and sold it with 25k miles. No issues. Bought a 2020 AT4 6.2 and sold with close to 33k miles and no issues other than a bad ignition lock switch covered under warranty. Currently in a 2024 LTZ 6.2 and other than rattling rear headrests (c'mon GM (said in a weak, raspy Biden voice)), no issues. If you rely on forums only, you'll never buy anything except a 2015 Tacoma with 220k miles.
I had an issue with a 2020 AT4 where when it was put into park, I would get a similar message. I can't recall exactly what the message said but it basically thought the truck was not in park. The stealership replaced a part (I do recall they called it some type of module) I believe in the steering column that eliminated the issue. I sold the truck and gave the new owner the paperwork, so no details. I'll look though just to be sure.
Edit: my post about it. Follow the link in there and it talks more about the issue.
I had a hat sitting over the sensor up on the dash. Removed it and it worked. You also probably saw the interior dash lights were extremely dim too which is "night time" mode.
If it were me, I would only buy the GM backed warranty that every dealer accepts. When I bought my 2020 AT4, Dennis Fichtner was the best price and came highly recommended. Search "warranty" on here and you'll see this name quite a bit. I sold that AT4 before the 3 year bumper to bumper expired, so I also was able to get a refund on the warranty (not full but close enough).
GMC Protection Products | GMC Protection
Dennis Fichtner
Warranty Specialist
Laurel Chevrolet
406-698-6355 Personal Cell
[email protected]
I have a 2020 AT4 with the Bose. I vaguely recall there are 2 levels of Bose, so not sure which one you or I have. I also heard the stereos got even crappier in the 22+ models. What I did was install the Kicker sub from GM. It made a WORLD of difference. I'm not sure exactly what it does but to me it seemed like it took over the bass duty from the crap full range speakers so they can handle mids and highs. The whole thing seemed to come alive. Granted, it's not going to do what you list above but for the money, it is a worthwhile upgrade. I'd search on this site for "Kicker" to see what others say. My .02.
I have not seen a topper/cap for a CP bed. Other than that, it's great. I throw split wood in mine w/o fear of denting the bed. Plus, it's a bit lighter.
Are you out of warranty? Sounds like a head unit replacement to me. If you do, look at upgrading to at least the 2020 version. I had a 2019 LTZ and changed to a 2020 AT4. The 2020 head unit is just better overall. I believe if you get a 2021 head unit you'll have wireless carplay/AA.
Check out White Automotive for a new until with wireless carplay/AA. Silverado / Sierra Wireless Apple CarPlay / Android Auto, Navigation and HD Radio Upgrade - White Automotive & Media Services (whiteautoandmedia.com)