Trans Downshifting twice

[s10mods]

I have put a 2001 6.0/4l80E in my 1993 Yukon. It is pretty much stock other than a cold air intake. My problem is while driving down the road and the trans is in 4th and in lock when I floor it the trnas shifts back to 3rd then in to 2nd. I am pretty sure I used a stock program, I just changed for my gears and tires and moved the shift points up a little. is it in my tune or do I have a internal trans problem?I have attached my latest .tun
Thanks in advance.

[joecar]

Post some logs.

If the PT 3->2 curve D0915 or WOT 3->2 MPH D0930 is met it will downshift to 2nd.

Looking at your file, do this:
- first, fix all the out of range values (not related to trans, but fix them).
- set all the throttle kickdown tables D0960,D0961,D0962 to 100%.
- each WOT upshift MPH D0910,D0915,D0920 must be above the correponding WOT downshift MPH D0925,D0930,D0935.

[s10mods]

Thanks, I will mess with it when I get home.

[s10mods]

How do you get rid of the out of range? I clicked on every one and they were set in range, I then saved the file then flashed the cal part of the file, and then I read it back and I still have out of ranges. do I need to do a full program?

[joecar]

The tunetool displays the max allowed value for any parameter that exceeds the max... so it looks like it's in range.

Do this, enter max-1 and save file, exit tunetool, re-enter tuntool, they should be in range now;
if you really want max value, then enter max value, save file, exit tunetool, re-enter tunetool, and if they are all in range now do cal-only flash.

[s10mods]

Ok got the out of range fixed, I changed D0960,D0961,D0962 to 100% and the WOT upshift MPH D0910,D0915,D0920 are above the correponding WOT downshift MPH D0925,D0930,D0935, but I still get a 4 to then 3 to 2 downshift. is it because D0930 is lower than D0915?
I also ran a log and it shows 4 to 3 then 3 to 2.

[joecar]

Oh, are you saying on going WOT it goes 4->3 followed by 3->2 instead of 4->2...?
(edit: hmmm.... takes about 1 second)

I don't know why it does that.

[s10mods]

Yea, I am stummped. I would think it should go from 4 to 2. I wonder if it's an internal trans problem? I did just have it rebuilt.

[joecar]

The GEAR pid is the commanded gear, and it is delayed... I think it's a PCM/tuning problem... for some reason the PCM is "loitering" in 3 on a WOT 4-2 shift... I don't think it's a trans internal problem.

Does it do this when doing a part throtte 4-2 (i.e. at 45 MPH in 4th, go to 80% throttle)...?

[s10mods]

you know I didnt pay attention to that, I only noticed it doing it under WOT. I dont think it does tho, I think it only jumps to 3rd, but I will drive it 2 morrow and let you know for sure.
BTW, can I use the bi directional controls to force a 4 to 2 downshift? that way I know it's a pcm problem.

[joecar]

If it doesn't do it at PT, then disable the WOT tables and just run off the PT tables (set D1206/D1207 to 100/100).

Yes, you can use bidi controls to command 2nd gear while in 4th...
(you know the warning, keep your eyes on the road, get an "assistant" to help you).

[s10mods]

I drove it to work today, and I noticed that no matter what, it shifts threw each gear every time. 1->2->3->4 4->3->2->1. even if I go WOT off the line and let up right after the 1-2 shift, it still shifts to 3rd then to 4th. I will have to try the bidi to see if it will do a 4 to 2 downshift. Maybe I should try another pcm. I have a spare, it would just cost me a license, but I plan to use that pcm in another conversion project later anyway.

[s10mods]

I tried my spare PCM with the same tun file and it does the same thing. I havent had anybody to ride with me to try the bidi yet. I guess my next thing is to try either the bidi or start with a different tun file with a different os from like a 2002 and see if that works.

[joecar]

So, it happens with PT downshift also...?

[s10mods]

yes, it happens everytime the trans shifts. It dont ever skip from 2 to 4 or from 4 to 2, even on upshifts, it shifts into 3rd every every time before 2 or 4.

[s10mods]

Well... I ended up changing OS's I went from a 2001 to a 2002 .tun file and started over. It worked correct on the first test run, now I need to modify the shift points and get rid of some codes.