2016 Sierra 5.3 A6 2-3 upshift too firm

[santeegreen]

A little bit of background, I had a decent amount of experience tuning the Gen III 4L60's, and when I purchased my new 2016 sierra with the A6 I was blown away at the amount of tables in the transmission section. I did purchase a "tuning book" from a very very well known company and applied the theory and settings they had to offer into my tune. The truck runs absolutely PERFECT with the exception of the 2-3 upshift, it hits so dang hard it's just not pleasant to drive. Under very light load it shifts smooth, and under 3/4-WOT it shifts great, its right in the middle is where i'm having the issue. I have tried extending the shift time longer, didn't help, I've tried lowering line pressure, didn't help. I've tried everything I thought would work, with no solution. I've tried everything I can think of and I am now here to see what help I can receive. If needed i'll get some scans and post, I can also post my current tune file if needed. Wasn't sure if someone knew right away what setting might help that i'm not seeing. Thank you.

**** Currently the truck is lifted with 35" tires with stock 3.42 gears, so shift points are adjusted quite a lot, intake, exhaust and that's it. ****

[GHuggins]

Your going to need to post the tune before anyone can help. Sounds like you might have disabled or partially disabled tm and on the newer "right around 2016" they changed some of the operating system to where they would default to max line pressure on shifts if you did that. Good news is you can go into the individual pressure settings per engine load or delivered tq and temps and dial things back to what you want per given cell... Doing it this way takes a lot of time, but all around a heck of a lot better to drive....

[santeegreen]

Andrew's 2016 Sierra NEW TUNED.hpt

[santeegreen]

Your going to need to post the tune before anyone can help. Sounds like you might have disabled or partially disabled tm and on the newer "right around 2016" they changed some of the operating system to where they would default to max line pressure on shifts if you did that. Good news is you can go into the individual pressure settings per engine load or delivered tq and temps and dial things back to what you want per given cell... Doing it this way takes a lot of time, but all around a heck of a lot better to drive....

Thank you for the quick response, and i'm hoping that's the case because I seriously am happy with the tune with the exception of that one shift. Very frustrating. Any help would be greatly appreciated.

[santeegreen]

under transmission "torque reduction" which is the master enable/disable for torque reduction on upshifts. When I disable that is when I get great shifts on all upshift EXCEPT 2-3. Again, although currently not in the tune, there are a lot more settings I had in there per my tuning guide I purchased but I took them all out and got down to just basic settings to try and narrow this firm 2-3 shift.

[GHuggins]

Ok, that's kind of what I thought you had done - under shift pressures - upshift - you'll find the individual pressure settings for torque... Lower torque areas - start taking some out and testing. You can play with inertia and other things, but this is the quickest and to the point. Just don't take out in the wot torque areas - you can log torque and see where you need to modify and do all of the temps for those corresponding torque areas...

[santeegreen]

Ok, that's kind of what I thought you had done - under shift pressures - upshift - you'll find the individual pressure settings for torque... Lower torque areas - start taking some out and testing. You can play with inertia and other things, but this is the quickest and to the point. Just don't take out in the wot torque areas - you can log torque and see where you need to modify and do all of the temps for those corresponding torque areas...

Thank you for the insight. I will be attempting some adjustments today in the tables you referenced. I though for sure I've adjusted these table previously with no improvement, but i'll try it again.

[santeegreen]

1.hpl

Attached is the latest scan after making substantial changes to 1-2 upshift and 2-3 upshift on pressure with no results. Seemingly taking even a large amount (in this case over 20 psi of line pressure in the suspected torque range areas with absolutely no change in shift firmness. Give it enough rpm and lighten on the throttle a bit it will feel like someone rear ended me it hits so hard. Literally only in 2-3 upshift. Take a look at the scan, the first 1-2 upshift was perfect, then 2-3 hit so frickin hard. Any help is much needed.

[JS264]

Do you have discrete shift torque disabled? I had a 2012 that would slam 2-3 no matter what I did until I re-enabled discrete shift torque and just adjusted the values to get a nice shift...

[santeegreen]

Do you have discrete shift torque disabled? I had a 2012 that would slam 2-3 no matter what I did until I re-enabled discrete shift torque and just adjusted the values to get a nice shift...

Currently the discrete shift torque is enable on 1-2 upshift and 2-3 upshift, all the rest and "0" (disabled). Being that 1-2 and 2-3 are a "1" for enabled, wouldn't that mean it should have a smoother shift?

[santeegreen]

I have "low" "mid" and "high" threshold tables, i'm thinking this might be the issue, i'll attempt to adjust these tables and see if there are any results.

[JS264]

That shouldn't be your issue then. What values do you have in the three cells for 1-2 and 2-3? And what are you oncoming pressure presets? On my phone so I can't just look at your tune...

[santeegreen]

That shouldn't be your issue then. What values do you have in the three cells for 1-2 and 2-3? And what are you oncoming pressure presets? On my phone so I can't just look at your tune...

Low all "0's", Mid all "221", and High all "443" lb ft of torque in every gear/cell. Oncoming Pressure preset for 2-3 shift as follows: 0 cell = 36 psi, 1 cell = 44 psi, 2 cell = 56 psi. These are all stock, and the tuning guide I have said not to touch these so I left them alone.

[JS264]

Opened your tune. I think its slamming due to your TM settings. Turn Tip-in, Flare, and Torque Reduction up shifts on to "no throttle" and bump up your pressures and increase oncoming pressure presets. Also use torque adders and inertia to speed up the shifts. Get them set right and the shifts are crisp, fast, and firm .

[JS264]

And set your torque factor adders between .7 and 1 instead of 0.0 where you've got them.

[santeegreen]

Opened your tune. I think its slamming due to your TM settings. Turn Tip-in, Flare, and Torque Reduction up shifts on to "no throttle" and bump up your pressures and increase oncoming pressure presets. Also use torque adders and inertia to speed up the shifts. Get them set right and the shifts are crisp, fast, and firm .

Made these adjustments, previously you had mentioned to lower the oncoming pressure presets, so now I raised them back to stock values. Shift speeds are just about what I want. Also set the torque factor adders to 1.0, and i'll see how the truck behaves tomorrow.

[JS264]

I didn't say you should lower the oncoming pressure presets, I just asked where you had them. I typically bump them up over stock a bit as well as line pressure.

[santeegreen]

I have added some to oncoming pressure presets, I added line pressure, absolutely NO improvements. Seemingly no matter what I do to anything in the trans tables it still shifts exactly the same.

[JS264]

Flash your stock tune on and see if it still does it.

[santeegreen]

Flash your stock tune on and see if it still does it.

I have done that and the problem goes away. The problem is literally when I have the master enable/disable for torque management disabled for upshift. The frustrating part is I absolutely HATE the way the all gears shift when TM is enabled. I don?t understand why it?s only the 2-3 upshift that is so harsh but yet all other gears shift perfectly and how I want them. And no matter what table I adjust for shift timing, or pressure, or volume, it never gets any better.