Yeah, it only did it between 1200-1500 rpm range if I was on a flat or slight downhill slope and lightly touching the gas. Unfortunately where I live and work there's a lot of driving in those conditions. It would even do it on the interstate though. You could feel it in the floor, pedals. Steering wheel, and center console. Almost felt like running over some very worn down rumble strips or rough grooves in the road. The first several times it did it, I looked at the console for my phone because I thought I had left it on vibrate and it rang sitting in the top cutout there in the armrest part.
I took it to the dealer and he said it was normal and was just where it was going into v4 mode. I explained that this doesn't have AFM like the 18s and doesn't go into "v4 mode". That was at 600 miles. At 1300 miles I took it back and the same tech admitted that my truck was the first 19 he had even driven and that he wasn't that familiar with DFM and how it worked exactly. I said if its normal, we should be able to go out and get in another new one and it'll do the same thing. Drove another, and it did but not nearly as bad. Obviously not normal in my opinion. They had no clue, so I contacted GM who was not helpful at all. They escalated my case to a lady that would only call me in the evening when i wasn't available. I would return their call during normal business hours and leave a message explaining I was only available during those hours. Then they'd call me back that evening. Went on like that for over a week and I got sick of it. Ate a huge loss trading it in on a 6.2, but MAN what a difference!