Erb2017

No need to Fast learn, I listed in my previous post what problems was causing the hiccups when I logged using HP while driving and my solutions. Torque management on the ECM(Engine) is what I was feeling, I could see TM pulling timing and throttle to keep torque demand tables at their listed torque numbers even though the engine can produce more than original GM programming. You have a lot of perimeters that add timing when cold such as IAT (Intake air temp sensor) that adds timing when cold, so with cooler denser air even more torque can be made causing the pauses of TM pulling timing and throttle. I raised these TM tables by 10% above 1500 rpm and 20% above 2000 rpm which smoothed the 3D graph and torque table making for much smoother acceleration without TM trying to hinder the engine making power. I also failed to mention that I zeroed the IAT table below 126 F because that too creates timing and throttle change pulls. Also disabling AFM/DOD helps tremendously because the ECM uses different TM tables, timing etc which causes even more delay. TM on the TCM side is set at 1.0 shift timing which is your shift speed. I do not recommend changing this to anything lower for these transmissions need that time to shift properly and smoothly. Changing to a better synthetic fluid and adding black bottle lubeguard friction modifier will aid the TCC to engage smoothly without shudder.

I would like to share my knowledge and hope it might help some of you. I used to be a transmission mechanic back in the 90's. I bought a used 2017 Silverado 5.3 6l80 LT with 36k miles back in May 2020. I too noticed that while warming up that the transmission would shutter, sometimes hunt gears etc. These transmissions are a clutch to clutch type which means that torque management must be used in order for the gear changes to complete, release of 1 set of clutches, then apply of next clutches(Gear engagement). I replaced the fluid and filter with Valvoline synthetic Dex VI, 12 quarts which is what these transmissions hold total. I also did the thermostat mod to the inline transmission cooler line which allows trans fluid to flow continuously because I have read where these thermostats fail causing overheating of the trans 230F+ which caused piston seals failure etc. burning up frictions and steels. The fresh syn fluid really smoothed out the trans shifts but I still had something glitching the trans while warming up and normal temp driving. I purchased HP tuners interface, downloaded the free software, bought 4 credits to unlock my 17' Silverado and began to study online. I did some logging of the truck and noticed that torque management on the engine side was engaging a lot above 1500 rpms meaning the engine was capable of producing gobs of torque down low but TM was pulling throttle and timing causing the little hiccups along with AFM/DOD 4 cyl mode making it much worse. I eventually decided to play with those settings to see what happens. I disabled AFM/DOD, then I added 10% in the peak torque tables above 1500 rpm and 20% above 2000 rpm and my truck became the smoothest running, shifting beast that I have ever driven. I kid you not, I logged making 350 lb ft torque at or below 2000 rpm. My neighbor has 2016 Silverado 5.3 with the nightmarish 8 speed trans and was driving him insane with all the clunking. After talking with him with what I had done, he decided to pay me to unlock his truck and try the same tuning with new fluid and filter change since he was more than due at 72k miles. His truck now shifts perfectly and is smooth as butter with more power and better driveability. He is totally happy with his truck now too! So I truly believe that the engine torque management pulling throttle and timing is what we all are feeling because these engines make a sh*t load of torque down low in rpm range. Getting those tables up some above 1500 rpm let the engine make the power without interruptions. Now mind you the TM on the transmission TCM must remain in order for the shifts to happen correctly and I have not had to touch the trans tune at all except I did disable the TCC lockup in 1st thru 3rd gear to stop the lockup madness when going between traffic lights in town. I truly hope this helps someone.