6L80 No upshifts

Hello everyone. Been on this board for some time now learning a lot from people's posts and need some help.

So I have had an L92 engine swap in my car from a 2007 Yukon Denali for some time now. I had been running a 4L60 from a 2008 Silverado and all worked fine up until I swapped out the transmission for a 6L80 from a 2013 Silverado. I took it out for a test drive last weekend for the first time since the swap and noticed that it was stuck in a gear. I didn't know what gear since I didn't have anything to read but I knew It was a high gear because it was revving around 3k above 50.

Long story short, while parked, I connected a scanner and noticed that when I put it in D, the gear would show 6 and then drop to 4. I was shifting back and forth and finally got it to read 1 in D. I thought everything was fine but on the test drive it stays in 1st gear with no upshifts.

I did have the engine light flashing with codes:
U0100
P0700

I have read many articles and all had many different solutions.
A) Incompatibility with the engine ECM and transmission TCM because of the difference in years, therefore I need to get an ECM from a 2010-2013 truck?
B) change transmission vin to match ECM?
C) something else?

I'll post tune file if needed

Thanks
JC

2013 6L80 TCM and programming is not compatible with a 2007 ECM and programming. 07 6L80s used a 24275871 TCM which was a one year only TCM for 07. 08-09 used 24275872 and may talk to a 07 ECM but not 100% sure on that. And the TCMs are picky about only using calibrations from the MYs they are for.

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Originally Posted by 2xLS1

2013 6L80 TCM and programming is not compatible with a 2007 ECM and programming. 07 6L80s used a 24275871 TCM which was a one year only TCM for 07. 08-09 used 24275872 and may talk to a 07 ECM but not 100% sure on that. And the TCMs are picky about only using calibrations from the MYs they are for.

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Thanks for the reply.
So should I get an ECM from a 2010-2013 Silverado or does it have to be only 2013 and would I be able to use it with my current engine? After configuring it of course

Thanks

10-11 TCMs are a different part # than 12+. If it was me I'd change the TCM to something that is compatible with your 07 ECM. IMO that would be the easiest and probably cheaper when you consider licensing costs too. You could change the TCM without having to re license the ECM.

Quote:

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Originally Posted by 2xLS1

10-11 TCMs are a different part # than 12+. If it was me I'd change the TCM to something that is compatible with your 07 ECM. IMO that would be the easiest and probably cheaper when you consider licensing costs too. You could change the TCM without having to re license the ECM.

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The valve body is also different, it would also need to be updated.

And this is what happens when people mix and match parts in a swap without planning.

Damn, then change the ecm instead and the bcm and speedo won't work.

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Originally Posted by 2xLS1

And this is what happens when people mix and match parts in a swap without planning.

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I researched just about everything for the LS swap except this one :doh: I just thought they were all interchangeable until now :shrug:

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hjtrbo
Damn, then change the ecm instead and the bcm and speedo won't work.

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I'm not worried about the the bcm or speedo since I don't have a bcm and the speedo works off of the Dakota Digital BIM-01

Thanks for everyone's responses.

it actually is possible to mix-match different year ecm/tcm's.... None of the software on the market happens to have the calibration tables for the relevant CAN settings defined is all.

But changing them 100% does work. I've done it myself.

I converted a 2006 VZ Commodore which came as a E38/T42 combo to E38/T43. I tested tcm OSes from 2007 to 2009 which even in factory form the 2009 tcm os will only work with a 2009 ecm tune or it throws U101/P700 codes.

I then placed an 06 ecu/tune into another of my cars which has a 2011 ecm/tcm setup, made changes to the tcm calibration to make it shift as expected & not throw dtc codes.

I did bit of a write up on my webpage/blog - https://www.torqueup.net/2024/06/11/...y-integration/