Z45

Do not assume any updates apply to your vehicle. Maybe the best thing to do is, leave well enough alone. I was at the Cadillac dealer once for a system software update fix (not a recall) for a known issue with fuel gauge inaccuracy in some CTS+4. Supposed to take 30 min. but as I was talking to a person in the showroom I spotted them pushing my car outside. Just about then the SM came over and said, while we were running the update the cpu froze up and we have to get a new CPU. I'm getting you a loaner, we hope to have a new one over night and I 'll have them bring the car to you when its ready. Came in at 9am Thursday, left with a 4 yr. year old DTS and got my car back late Friday, good as new. I was under the 3yr B>B warranty. Imagine the cost if not covered by warranty?

Mann+Hummel since 1941 per their web site

First brands was the holding company that owned Champion Labs and Fram, + many other auto parts companies. Those brands are not making filters anymore. Premium Guard Inc. (PGI) acquired the intellectual property for both FRAM and Champion Labs. Premium Guard is a similar company as Champion Labs was.

Friend was telling me ordered a 2025 Yukon Denali. Was waiting for it to arrive (was told built and in transit) and it was not showing up. So one day he goes down to the dealer and as he drives through the lot he spots this Black Yukon Denali sitting outside of body shop area in primer, masking tape and paper. They are repainting the top parts, hood and roof. So he moseys over to a worker and asked, what happened here? Guy says, brake leaked on it in transit. He walked away from buying it because they never intended for him to know that.

Having owned 4wd vehicle since the 1970s I find there are varying opinions on how to use 4wd, every owner is an expert in their minds. IMO, 4LO is the appropriate gear and what I would use, You have to feather the gas to avoid spinning tires and the lower the gear the better chance. But like I said you will find those that think their method is best. I live near a boat launch. Yesterday there was a new Ford Maverick pulling out a pontoon boat almost 2x its size, they had no problems and they don't have a LO range. True story. One winter day not long ago I was coming out of small town post office and there was a F150 4wd parked in front and was stuck foot deep snow ruts. I knew the lady so I asked her to put it in 4wd (wondering why in the middle of a 2-day snow storm she wasn't). Her reply surprised me, "my husband" (the expert) told me not use that because it uses too much gas. She finally got unstuck spinning in 2wd which likely used more gas than not.

Some tires have more tread depth thus a different circumference. Tread depth will vary by type, brand, and model. https://www.tirereview.com/science-behind-tread-depth-passenger-tires/

Dirt settles in the door drain holes and traps water....lower corners of inside door skin.

These codes don't automatically clear if you fix the problem?

I have the GMC accessory (REV) cover installed by dealer. Ordered with the truck. They did a very good install job, can't find a single issue. Some water gets in around the tailgate but no where else. You can see daylight around the tailgate but that's not the covers fault. Installation is means everything. Guys at my dealer were seasoned pros, not inexperienced here today good tomorrow types, like many dealers employ for these jobs. I don't mind paying for a professional job.

Tires of different brands may have different circumferences (or radius) even if they are the same size.

Problems are blown way out of proportion due to the internet. The same experiences get repeated over and over again till it sounds like a real problem. There is NOT an vehicle out there that does not have some issues. Building 100's of 1,000's of vehicles with 1,000's of parts from various suppliers all over the whole, some quality control issues are going to make it through the process. The internet is full of misinformation often designed to change readers opinions. I have had 2 trouble free years with my 2024 Sierra, don't tow anything heavier than a 2026 Ranger NorthStar and mostly a around town. I personally know 3 others with same engine and no issues, 2 are LM2 version and 1 is the LZO, all three happen to be GMC's. All of these owners are older persons (40+) so that may have a lot to do with it. No modifications, no big tires, suspension hacks etc, just normal use. One who has a 2021 LM2 has over 100,000 miles and travels estimating projects for the electrical contracting company.

Was back in early June 7th as I recall

Don't know if all will be able to see this. Valvoline Cuts Dexos Claim from Synthetic Oils https://www.lubesngreases.com/lubereport-americas/11_27/valvoline-cuts-dexos-claim-from-synthetic-oils/

dexos began as an effort for GM to control the oil change market because the Quick Lube Industry was eating into dealer service department profits big time. So they attempted to get other oem’s to develop standards as well and that would make it hard for Quick Lubes to compete because all the oems would be different. GM faced lot of industry push-back, mostly the quick-lube industry and they went to licenses. Still GM it making a ton of money (est'd 30-40 million in 2025) off the license structure as they charge a hefty fee to get oil tested then require a royalty on ALL gallons sold applicable to GM vehicles.

I would be surprised if the diff's were not filled (with the cheapest gear lube) at the axle factory before being shipped to GM. If you ever watched them building trucks they install the axles and all suspension parts with the frame upside down and then turn it over before its time to install the engine. Too much gear lube in a axle can be worse than not enough especially with a lower quality GL where is get whipped up with entrained air (foam) weakening its ability to lubricate.