4l80e upshifting when held in gear

[joecar]

Taz has a good point... if VE table is close then trans line pressure will be closer to matching engine torque.

[EagleMark]

Try this (attached).

You have a shift kit, and you're seeing soft shifts...? If you still get soft shifts with the attached file, then try setting the shift times tables to 0.2 seconds all across.

^^ Read above^^ He said set table to! Not add to!

I tried your file and it still didn't seem to shift that hard so I went ahead and added the .2 to all three shifts. Should I go up more? The 1-2 seems slightly better, but the 2-3 is still sluggish. The trans is a fresh rebuild, and I had him put a Trans Go HD-2 shift kit in. It shifted great when I first started driving it (about a month ago) and slowly has gotten worse. I really appreciate you guys helping me!

"Slowly gotten worse" is a sign the adaptive learn is working against the shift kit. When you added .2 you made it worse for learn.

Although this thread was for 4L60E I think a lot of it will help understand, it did to me when I started it. Also look at first post! I linked all really good threads on transmission tuning.

HTH!

[EagleMark]

Forgot to add the link and having issues with "Edit Post" so here's the link:
http://forum.efilive.com/showthread....ock-3rd-at-WOT

[Taz]

..."Slowly gotten worse" is a sign the adaptive learn is working against the shift kit. When you added .2 you made it worse for learn ...

As long as there is no concurrent mechanical issue, then you are probably right on the money. I always disable the Low Pressure Adjust (to keep the PCM from reducing pressures), but keep the High Pressure Adjust active (more pressure is rarely a bad thing).

[tdmkr496]

How do you disable the Low pressure adjust, zero out all the values?

[tdmkr496]

^^ Read above^^ He said set table to! Not add to!

"Slowly gotten worse" is a sign the adaptive learn is working against the shift kit. When you added .2 you made it worse for learn.

Although this thread was for 4L60E I think a lot of it will help understand, it did to me when I started it. Also look at first post! I linked all really good threads on transmission tuning.



HTH!

I typed it wrong, I set to, not added to lol. I will set them back to 0.0

[Taz]

How do you disable the Low pressure adjust, zero out all the values?

Yes.

Try the attached tune ... use caution. Without knowing how much the fluid flow / pressure was increased mechanically by the shift kit, I am merely guessing at a starting point. The attached tune could end up being extremely harsh and unusable, or fairly close for drag strip use.

I also put some torque reduction back in, just to be safe.

This tune is intended as a starting point for developing desired shift firmness. It will not hold first gear if manually selected (no stock 4L80 tune will) - I charge a fee for that service - if that is something that you may need down the road, just send me a PM.

[tdmkr496]

Thank you for all of your help but it looks like the pressure control solenoid is bad. I have one on the way, I'll let you guys know as soon as I get it back running.

[Wolfie]

At the risk of coming across like a dummy (yeah, I've been called that) I have forgotten much more that I probably will learn since I've kinda parked my van,
I'm assuming that it doesn't really hurt the tranny to add in lots of base pressure (D0701,D0702, D0703)? Mine seems to me to shift really soft, even with disabling torque reduction, and zeroing out the desired shift times.

[Taz]

Hi Wolfie ... I can email you one to try if you want ... the one I posted in this thread is far too harsh for a daily driver to use !

To answer your question, you can add quite a lot of pressure to the 3>4, a fair amount of pressure to the 2>3 shift, and a cautious amount of pressure to the 1>2 shift.

With a vehicle like yours, with an active Tow/Haul switch - two separate profiles can be developed. One for daily driving, and the other for towing, drag strip, etc.

Cheers,
Taz