NHTSA Complaint #11711937 — 2025 GMC SIERRA 1500

I have the 6.2 L87 with the 10 speed transmission in my 2025 Sierra. At cold start, when auto stop restarts the truck, when the truck downshifts under 20 mph down to 12 mph the engine or transmission makes a chirping/squeak/squeal sounds. Several repair attempts have been made, parts replaced. According to GM and their “field engineer” this is a “normal characteristic of the dfm system”. They claim that it has to do with ignition timing. Not my first dfm truck, but it is the first to make this noise. There is not very many components in “the dfm system” that can make a metal on metal squeak/chirp/squeal sound other than lifters/pushrods, but the noise could be coming from the transmission/bell housing area. I am fairly certain this is an early warning sign of engine or transmission failure. Truck currently has 7,800 miles. If this was an actual “normal behavior” for this engine, all of them would make the same noise. But out of 7 other trucks with the same engine and transmission that i have started/drove, none of them made the noise. It has made this noise since i purchased it brand new. A Gm field engineer “looked” at the truck 3 weeks ago, and I still have not received any paperwork on what they actually did when diagnosing it. Not a single document from the dealership or GM, regarding the 4 days that my truck was at the dealership on the 4th repair attempt. Gm technical service bulletin I was referred to by the dealership is 22-NA-218 Will update this complaint when failure occurs.