L5P RPM surge during decel
I purchased a brand new 2019 2500HD Duramax and at 1200 miles I noticed the engine surging during decel. When coasting to a stop from ~30mph (any speed as long as the transmission is in 2nd gear or higher when beginning the decel) when the truck is around 15mph, the RPM begins to surge 150-200 rpm. The RPM will continue to surge until the truck decels below about 12 mph at which time 1st gear engages and normal decel resumes. If on a slight downhill where the truck will maintain ~15mph, the surging will continue.
I brought it to the dealer and replicated the issue for them (now at 2200 miles and I can replicate the surge almost every time on decel). The dealer acknowledge this did not seem right. They ran their standard tests and did not find any issues. They then contacted GM corporate who took one of their vehicles and also replicated the problem on their vehicle! My dealership then took another truck from their lot and were also able to replicate the issue. Since all of the trucks had the same problem, GM claims this is 'normal' and is not an issue.
Has anyone else reported this issue? Can you go test your truck and see if you can duplicate the issue? If so, please bring it to your dealers attention. At the direction of my dealer, I filed a complaint with GM corporate to get the issue looked at further.
I'll post a video below if I can get it to upload. Thanks!