6l80e surging at light throttle

[Jonblarc7]

2014 L86 sierra with a 6l80E, 3.42 and 22x12 33" tire.

After making some adjustments to my trans now I'm getting a 200-300 surge at light throttle. Mainly while cursing around 38-48 mph.

I tried it with the TCC disabled in fourth and with lock up speed in 4 reduced to 42 mph the TCC is disabled in 1st 2nd and 3rd. It made no difference on the surge. I also tried it with 3>4 shift speed increased 3 mph and 5 upstift increased 3 mph. And I still had a surge but maybe slightly better.

2014 slt e85 trans 2-20-19.hpt

[Jonblarc7]

I think it might be that I have TCC apply 4th set to 42mph and release set to 41mph

the

TCC apply 5th set to 45mph and release 40mph. Which is lower then my release point in fourth and I'm confusing the computer. Any thoughts????

[DrLoch]

Do some reading should help you.

https://forum.hptuners.com/showthrea...ly-Issue-Fixed!!!
https://forum.hptuners.com/showthrea...ckup-Questions
https://www.hptuners.com/forum/showt...183-6L90E-Help
https://forum.hptuners.com/showthrea...highlight=6L80

[Jonblarc7]

Thanks I ended up setting 4th 5th and 6th back to stock then eliminated lock up in 1st 2nd and 3rd.

It?s much better now I?m just not sure how much I need to bump it up from stock

[DrLoch]

I'm not familiar with a truck so pardon my ignorance. Does the truck have a standard and sport mode? I have a STS-V with the same trans exception being it has a 2 disk torque converter. At highway speeds I was having a hunting issue with TCC, pressure was lowered until a split was detected then pressure would be applied until it locked up again. Drove me crazy. I changed the apply pressures and times like suggested and that fixed my issue. Not lockup feels like another gear. I also changed it so it will only lockup in 5th and 6th gear at highway speeds in normal shift mode, my wife's mode, adn not at all in pattern B which is my sport mode. It still locks up in TU /Tap down mode which I'm going to eliminate as well,

[Jonblarc7]

It has Tow Haul mode which I?m not going to touch because it pulls so good already and I use it a lot during to summer pulling my boat. Even with it back to stock lock up in 4th 5 th and 6th. There is still a slight 100 rpm slip around 35 to 40 so I going to work on adjust the pressure. I just not fully sure where to adjust it so I got to read up on it some more.

[Jonblarc7]

On of the problems I?m having. Is mine is a 2014 DI 6.2 with a 6l80. And I do think I have some of fields people are talking about.

I only have TCC Pressure
Apply Ramp and. Max Pressure

My max Pressure stock is 119.9 psi. I see a lot talk about 50 psi. So I guessing I need to make my changes under Apply Ramp

[Jonblarc7]

Here are the options on my truck. I assume i need to change the AC Off 1st tables. But do change that whole table or just the bottom. Remember I have the TCC disabled in 1st through 3rd.



HP TUNER.PNG

[Jonblarc7]

I adjusted the table for AC off in 4th 5th and 6th to be all 0 on the lower line then the next line up.

Then I added 20% to the TCC Pressure>Apply Ramp

But i think that was the wrong thinking and I should have taken 20% out of that table.

here is the log before the last adjustment and the latest tune. I'm going to go back and take 20% out of that Apply Ramp table because it's worse now.2014 slt e85 trans tcc pressure 2-26-19.hpt2-26-19.hpl

[DrLoch]

On that tab I have 2 more items, Regulator Gain and Regulator offset. Also my Adapt Min is now zero and Adapt MAX is 150 kPA.
Here is my TCC Apply Pressure Ramp to give you an idea. Remember your vehicle is heavier...
.TCC Apply Pressure Ramp.png

[Jonblarc7]

So your basically maxing it out from 78.3 at 0

To max torque and 300 max slip area.

So if I added 50% to the whole chart it basically would do nothing?TCC.PNG

This is what mine looks like.

[Jonblarc7]

So I set all the Torque converter Apply/Release back to stock. But I upped the TCC Pressure>Apply Ramp 50% and the TCC Pressure>Max Pressure 50%. I also 0 out TCC Desired Slip tables 1-6 and disabled Use DoD Slip function and disabled those tables.

That seem to cure everything. I just had the TCC Apply/release>normal to high in 4th,5th and 6th. I got bad information on another forum and set them to high from the get go.

I might go back and add 25% more to the Apply Ramp because I still have just a tiny bit of slip. But not enough to feel.

[DrLoch]

Sounds like you're moving in the correct direction. I'm quite happy with mine now, when it was acting up it was a major PITA. I had to replace the TEHCM in mine. It decided it didn't want to be part of the shifting program. Hard shifts, sliding shifts, go into neutral at a stop and then slam into gear.... you get the picture. Replaced with a Dorman reman be fine now.

[Jonblarc7]

Yep finally understanding the graphs and what they do. Before I was scared to change the area I needed to change. I thought I always need to change the whole graph.

[DrLoch]

Once you get the trans tune moving in the correct direction it becomes easier because you can feel the cause and effect in the shifting. At first it's hard to understand which direction you need to go in. I did a lot of reading I included the posts that helped the most. The problem I had but didn't know was that my TEHCUM was failing which made results inconsistent so I was chasing it before I finally came to that conclusion. Once I started seeing/feeling predictable results from any changes I made it made it a lot easier to adjust the trans tune to my liking.