I have been dealing with the annoying things GM has done one by one. One of the last ones that is bugging me is the feel of drivetrain slop when you go from zero throttle to any throttle. Those transients lead to a jolt.
After doing a little research and playing around, I narrowed it down to the driver demand table as a possibility to help. When you go 0% throttle it commands a negative torque. So on and off the throttle you basically command negative and positive torque - engine slowing you down or speeding you up.
Now, keep in mind the negative numbers will help avoid the "run-a-way" feel and in cases where it is too positive, it may actually accelerate you if you are are 0% pedal position.
I looked at earlier truck calibrations and the 0% pedal torque was about 2x what mine is (2018). I ended up leaving the top end of the driver demand table (around 80 MPH) nearly the same. Interstate driving felt fine. The 40-60 MPH range was rough.
I increased the value to around -400 in other areas and did some smoothing. So far it seem to have made a big improvement. I am playing with the balance of no jolting while still maintaining decent speed control. The 50 MPH range is tough if it is in 8th gear. +/- 5 MPH outside of that it is fine. I have also noted improved fuel economy from better coasting, quite frankly, actually being able to coast a little before essentially engine braking. I used to be able to get off the interstate at 70 MPH and coast to a stop by the end of the off-ramp - sometimes even having to get back on the throttle. These were flat 0.25-0.50 mile off-ramps.
Anyway, long story short, I was curious if others have tried the same. If not, I am offering this up as a potential solution to see if it would help others. Here is what my current driver demand is (attached).
I should also note I left tow mode along in the 0% and 2% rows. I wanted to maintain engine braking while towing and also give me the "emergency exit" if I had issues during my tweaks. I also put Amsoil in the rear. I heard that helping others with the slop, if that was the issue, and figured why not give it a shot. It didn't really help once the fluid was up to temperature.
EDIT - for some reason I can't get a file to attach...