6L90 Shift Pattern Type

Alright guys New to tuning the 6 spd trans. I got a deal on a 2011 6.0 2500hd to use as a work truck, knowing it wasn't exactly right. It had a jasper trans put in right before I bought it. It always seems like its in the wrong gear. i read it and the first thing I notice is the Shift Pattern Type is

Pattern A- Pattn 1
Pattern B- Normal

It explicity stated on the editor its recommended not to change these values.

But shouldn't they be

Pattern A-Normal
Pattern B- Trailer

I know the tcm is in the trans , I wonder if it was just a jasper goof up.

What are your guys thought?

Not a goof up. There are several different operating systems and calibrations put into these trucks/transmission and it can differ between model years too.

A 2011 file can have different settings than a 2012 file. I notice this alot with the GMT-900 platform. My previous 2012 silverado used normal/trailer where as the 2010 truck I owned before that was Pattrn 1 and Eco Mode.


Just tune the transmission to how you want it to act through all the transmission related tables. Like shift speed, shift timing, pressure presets and shift pressure settings.