HP Tuners Modifications for GM Trucks.

[TheBigCheezeBall]

I finally got around to trying this out last week. I made the changes in Tow Haul first to see how I like it. Right now it will only lock in 5th and 6th, and only under 20% throttle. It will stay latched in until 37%. I wanted some room between the lock and the release to prevent it from coming on and off too frequently. About to take a long road trip, so will let you know what I think when I get back.

After a good long drive I think I still have some work to do. It releases a bit to easily, so need to revisit my tables. Also it seems to do what ever the hell it wants in cruise control, which is a bummer. Will update if i get a chance to tweak things. I do really like the idea over all though. The extra RPMs and “squish” on a hill makes it seem like it isn’t struggling anymore. I do get up to about 175 degrees on the transmission though, so need to keep an eye on it.

 

[Marky Dissod]

It releases a bit too easily, so need to revisit my tables.

The more precisely you describe this particular behavior, the sooner you'll figure out how to fine tune it to suit your tastes.

Also it seems to do what ever the hell it wants in cruise control, which is a bummer.

That's 'cause cruise control behaviors are a separate set of tables 'n stuff; it's NOT the normal tables.

I do get up to about 175F on the ATF though, so need to keep an eye on it.

That's roughly the ideal temp for long-term Dexron3 operation, so Dexron6 (as well as Dexron HP-LV, & Dexron ULV) should be very happy at 175F, no worries.
Anything under 203F/95C is good enough for 25,000 miles between ATF changes.
(ATF temps between 212F & 230F are worth, like, 2-3MpG, plus it makes you have to come back & change ATF more often, so winwin for GM.)

 

[TheBigCheezeBall]

That's 'cause cruise control behaviors are a separate set of tables 'n stuff; it's NOT the normal tables.

Yeah, that’s what I thought too, but the shift pattern value never changes based on cruise. It also behaves like you would expect for upshifts and TCC applies, but seems to ignore downshift and TCC release guidelines. I will keep digging around and see what I find.

 

[mikez71]

Make sure you have the latest beta software..
One person submitted a suport ticket and got the 'cruise control shift override' option added for their '18 silverado.

2018 silverado 5.3 / 6l80e - shift points while using cruise control

hey all, i've been playing with this for awhile and i have my shift tables set up pretty well. but i haven been able to figure out how to adjust the cruise control shift points. i have confirmed repeatedly with logging that, while using cruise control, it will not downshift out of 6th or 5th...

forum.hptuners.com

If you can't find it in the latest beta release, you should submit a support ticket as well.
The times I have submitted a ticket, they have responded with their findings within a few weeks..