Gentleman,
I have 2023 6.2 Tahoe.
It suffers from the GM 6.2 Squeal Chirp.
It squeals when stopping at 14 miles per hours (this one can be cancelled by driving in L9 to deactivate the DFM).
It squeals during every gear shift (regardless of L9). Although very faint.
It squeals when accelerating from the mid 30's to mid 40's (regardless of L9)
It squeals when cruising on the highway in the low 70's (regardless of L9).
Have any you that have the squealing/chirp experienced it when cruising gentle around 39-40 mph and moderately accelerate back up to 45-48 mph. This happens in D or L9 so it's not a part of the DFM.
Your help would be greatly appreciated!
After further investigation, it appears the squealing from when accelerating from 39 to 45 and the squealing when cruising around the 70mph range is coming from the exhaust flapper valve. I can duplicate it in my driveway and make it go away by forcing the flapper valve open. I may have to fight this until they replace the OEM exhaust. What I don't understand is why is it still happening in L9 mode with the DFM off. Does the flapper still stay slightly closed when just cruising on a gentle throttle?
For the other squeals...
The chirping/squeal when cracking at the 14 mph range, and the auto/stop start, and the chirping/squealing startup is related to the DFM and spark retard per the bulletin.
I can eliminate the the Auto Stop start and braking squeal by driving in L9 and disabling DFM.
I really thought Escalades didn't have the issue since they have more insulation than the Tahoe and Yukon, but yesterday I was at a light and an Escalade came to a stop next to me and I clearly heard the squeaking. Then on the way home, I was riding next to another Escalade and opened my passenger side window and stayed beside them and when they came to stop, there it was again. Sucks.