No kickdown/passing gear 2 weeks after tune 2016LML

So this is been going on since new or at least close to it. Bought new truck, tuned for a bit more power because it did not kick down well at 55mph and dealer said it worked normal. Use manual shift button and worked awesome. It seemed to work better and kickdown 2 gears after tune but slowly fade back to it's old habbits.
Fast forward 3 years later and fully tuned it will completely loose passing gear after 1 to 2 weeks of driving. Stab the throttle at 50mph and 6th is what it stays in. Download the same engine tune (not the trans tune) and it will downshift 2 gears at 70mph in standard mode or tow haul. 2 weeks later, no kickdown, re-download tune, trans will kick down. Turned off all adapts in trans tune, download and again works perfect for 2 weeks then no kickdown again.
Any Ideas are greatly appreciated !

Turned off all adapts in trans tune[/QUOTE]

Have you tried clearing the Adapts and putting the TCM back into Fast Learn mode? I haven't done it with EFILive, but I believe it can be done in the DVT section.

Have you considered getting the TCM tuned properly? Since 06, the 6-speeds have never had an intelligent 4-5-6-5-4 shift pattern. 5-6 should never put the truck under 1800 rpm, nor drag down to 1500 before shifting back to 5th (without your foot intervening), and you should NEVER see conditions for a 2 gear kickdown. But the factory tuning does just that. In my opinion the delay makes the truck dangerous when passing power can be life or death. I would get some new TCM tuning. I would offer, but I don't offer programming where streams have been discontinued. By the time I obtain your factory tune from GM, and license the TCM, the cost is too high to make a profit. You have a T14 TCM I assume.

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Originally Posted by killerbee

Have you considered getting the TCM tuned properly? Since 06, the 6-speeds have never had an intelligent 4-5-6-5-4 shift pattern. 5-6 should never put the truck under 1800 rpm, nor drag down to 1500 before shifting back to 5th (without your foot intervening), and you should NEVER see conditions for a 2 gear kickdown. But the factory tuning does just that. In my opinion the delay makes the truck dangerous when passing power can be life or death. I would get some new TCM tuning. I would offer, but I don't offer programming where streams have been discontinued. By the time I obtain your factory tune from GM, and license the TCM, the cost is too high to make a profit. You have a T14 TCM I assume.

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Controller is a T87. Just put in a stock file for the engine tune and it works awesome. It will kickdown 2 gears at 70mph. and 200 miles later no kickdown unless below 55mph. Not even a 6-5. So if i go 54mph and slam the throttle it will 6-5 and just kind of bog along. It was doing this brand new before a tune was ever installed and GM said it was supposed to be that way. Just realized recently after a download it works good for a couple hundred miles then passing gear slowly fades away. So it must have adapt tables that I can not access with EFI or HPT. Do you have access to tables not seen by the rest of us ?

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Originally Posted by Butchh

Turned off all adapts in trans tune

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Have you tried clearing the Adapts and putting the TCM back into Fast Learn mode? I haven't done it with EFILive, but I believe it can be done in the DVT section.[/QUOTE]

Yes, with my Snap On scanner.