I'm looking to tune my Gen V L83 Silverado and find the Tow/Haul mode transmission shift points to be confusing, look at the attached screenshot. I would think Tow/Haul mode would pull shift upshift speed higher for a given throttle input, for example 25%. But yet Pattern B is set to trailer mode and the upshift speed in Pattern B is lower than Pattern A, 19 vs 27.
Thanks for the help.
It is whatever you want it to be. Tow haul will disable TCC so you can effectively have a higher rpm at lower throttle percentages. Helps a little with the mileage you lose when you don't have TCC. You can change it to whatever you want. I would personally leave TCC off for the tow/haul mode though. Don't want to put that much load on that converters clutches
According to the scanner, when I press tow/haul my transmission goes to pattern A. My best guess is pattern B is for truck with max trailer package with factory trailer brake controller. On my 14’ Drii
Ve is normal (D6), manual is normal (d4) tow/haul uses pattern A, all others are on normal. I’m about to deep dive into this because I was TUTD to activate in manual mode and want the tcc to pretty much stay locked unless shifting or under 1400 rpm’s.
Why would you want the TCC locked in lower gears?Originally Posted by LowlifeLowrider
This is kind of a weakness of stock 6LXXe Torque Converters.
Not to mention some spark knock issues.
IDK what the heck that table is for TABLE A : not going to shift from 1-2 until 27 mph at zero throttle and 3-4 shift at 60 mph at low throttle..
That table is screwed... What a disaster.
Many times when towing, your tps is many points higher for any given speed so I don't really worry about it at under 25% TPS
It's the mid TPS % that really counts.
But make it what YOU are comfortable with.. I tweak my stuff all the time to make it "just right"
maybe not wrong, map is in km/h.
My guess is this...
Pattern TYPE is just a label for what you have selected (normal or tow mode) It is different than Pattern A/B MAPS.
MY 2012 has pattern type A = 'normal', and it happens to be using the 'normal' map, but pattern type B = trailer, which is actually using pattern A map. Pattern B map is 4wd lo.
Is it just a label for the mode you're in, or does it actually select a different map when you change the type? If it does change the map, the map name and type name do not necessarily correspond.
Looking at yours I believe its the same, normal map is normal mode, pattern a map is tow mode, pattern b map is 4wd lo.
Last edited by mikez71; 05-20-2024 at 02:57 AM.
I know this is an old thread just wanted to add some input in case other people come across it. If you guys are unsure of what pattern you are in?use the scanner Channel ?Shift Type?. It will show you what pattern it is referring too. Not all vehicles are the same. There are various configurations you can assign your PRNDL position too. There are also limitations depending on the operating system. On the Gen 5 trucks. Pattern A is Tow/Haul, Pattern B is when you put your shifter in manual mode and let the truck auto shift (these are not the TUTD safety shifts).
Good advice.. it's what I do. The LSA CTSV and ZL1 default to pattern B.. So its good to stay on top of what is being used by logging that channel.
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