Factory tune shift oddity

**Mudsport96** · 03-08-2021

Hey all, i am new to tuning, and thought id ask for some input. Quick background on the truck.

I have a 2006 ex cab z71 with the L33 and 60e. Its on its 3rd transmission, BUT but it does have 400k miles on the truck. Father in law has owned it since 17,000 miles and gave it to me to fix for my daughter when the trans started flaking out again. No big deal to me since that meant she would have something to drive other than my Nova.

Ok to the issue. The truck has ALWAYS had a goofy 1-2 shift. Anything less than 25 percent throttle its just a slow sliding shift, worse than my 06 tahoe. Then 25 to id say 50 percent throttle its a slide with a quick slam into second. And finally above 75 percent its a flare slam into 2nd gear.

But 2-3 and 3-4 have and are always fine. Tps works and reads fine, coolant temp sensor fine. So no external sensors should be causing this, and since all 3 transmissions over 400k miles have acted the same i can only figure it is the shift tune. If i upload the factory tune can someone dissect it or give it a look? I only have tunerpro and there isnt currently an xdf to look at the 7811 operating system.

**In-Tech** · 03-09-2021

Try this and post back. You should only to a calibration write and not a full clone since this was done on my bench test puter.

**Mudsport96** · 03-09-2021

Thank you, ill give it a shot tomorrow since im at work now. Ill try it on a spare p59 that i have so i dont brick the original.

**In-Tech** · 03-09-2021

Do a full clone to your spare with the stock file and then see if it will run, otherwise will have to turn off the vats

**Mudsport96** · 03-09-2021

Yeah i was going to clone the stock file then write your modded one to it.

Funny thing is the notation under my user name says carb and points... I can tune those in my sleep haha. Even when it was 10 degrees last month the nova fired off with one pump to set the choke.
This stuff is a little more complex

**In-Tech** · 03-10-2021

Any luck?

**Mudsport96** · 03-10-2021

Sorry for not updating. Had some family problems, will be another day or 2 before i can give a confirmation on whether it worked or not. I am eager to try it, just was forced into the non-priority pile for a few day.

**In-Tech** · 03-11-2021

No worries, just curious.

**Mudsport96** · 03-13-2021

Ok. I bench flashed the ecm and it took. Reread it and its good, just have to get time to swap out the computers and i can give a final answer. Thanks for your patience.

**Mudsport96** · 03-14-2021

Well, i copied the original ecm. Recalibrated it with the trans modded file and the vats wont let it start. So, ill start over by just copying the original again and see if it starts that way. Then retry the trans flash file.... i did see today there is a tsb on the factory os to have it updated. Don't know if they will honor that 15 years later though lol.

**Mudsport96** · 03-15-2021

Ok update, so if i just clone the ecm it starts and runs fine. But the shift mod tune it does not start.

**In-Tech** · 03-15-2021

Clone the pcm like you did, then just do a calibration only write to that and all should be fine.

**In-Tech** · 03-15-2021

If you still have problems, I'll clone a pcm here to your .bin and then throw my mods on top of it and re-post the .bin file. I'm not sure how pcmhammer does the calibration write process, maybe it doesn't work like I think. There is 8 modules inside besides the parameters section where your vin, serial, cam sync, vats, etc is located.

**In-Tech** · 03-15-2021

I am not 100% confident this is a file that will allow a restart because pcm hammer does a clear codes at the end which may or may not require a VATS relearn and/or cam sync learn. Let me know. This should have all of your parameters included. Do a full clone flash.