No speed signal from L96 / 6l80e - No shifting

[Stillwater937]

I'm new to tuning so take it slow please be detailed in answers and question if you can. I have a 2017 L96 6.0 and a 2018 6l80e both from 2500 Silverados. I installed them in a 82 C10 using a PSI conversions harness/pcm. Part of the deal with this harness was I had to send in my TCM from the 6l80, I assume so that can flash them to match. Today I got the truck down off the jack stands finally, and started idle tuning. Once I got it to stay running without the use of the gas pedal I decided to take it around the block with VCM scanner running. However I don't get any speed info thru the scanner, and the trans doesn't shift out of first. Attached is the tune PSI gave me (V1.0), and the tune I made changes to the idle RPM and airflow (V1.1) and a log file of the short drive. Any ideas would be helpful. Thanks.
C10-V1.0.hpt
C10-V1.1.hpt
Short drive no shift.hpl

Edit: I added the input/output shaft speeds to my logs but they also stay at 0.

[drewlawrence]

Did this ever get resolved? Was it an issue between the different year ecm and tcm?

[blindsquirrel]

Was it an issue between the different year ecm and tcm?

No.

The ECM/TCM are programmed as a 2013 Silverado 1500 W/T. Cal IDs are correct for that year/VIN/hardware. All the various trucks here, the 2013, the 2017, the 2018, all call out the exact same TCM service number. So the 2013 calibration is perfectly fine being flashed to the 2018 TCM.

[drewlawrence]

@blindsquirrel. Is it possible to use hp tuners to change the os of the tcm? I have a 2013 e38 ecm with a 2014 6l80e tcm, currently I have no errors and can read gear position, trans fluid temp, and the speedo. But for some reason it won't shift out of first. Thinking it might be an os issue.

[blindsquirrel]

Sure you can change the TCM OS. Can't say if that will help without more info though. You've jumped onto the end of an old thread, haven't posted any files, without knowing what you have it's impossible to say if it should be something different.

[drewlawrence]

Sure you can change the TCM OS. Can't say if that will help without more info though. You've jumped onto the end of an old thread, haven't posted any files, without knowing what you have it's impossible to say if it should be something different.

My apologies. I was digging through old strings to see if there was anything that I could go after.

My build is a 1992 C1500, 2013 5.3L with a 2014 2wd 6l80e. Addons include -GPI VVT LLT1 Cam, DOD Delete, Trunnion upgrade, LS3 Springs, SE LT Headers, SE 3" True Duals.

My problem is that I cannot get the trans to shift out of first, I have no codes for the trans, but I do see gear position, current gear, trans temp, and a serial speedometer output.

Attached is a file from last week before I changed the VSS output to fitted to get the speedo to work. I can post a recent copy and log tonight.

[drewlawrence]

@blindsquirrel I did some more digging. Is it just a simple segment swap to do this?

[blindsquirrel]

You can't turn a 2014 TCM OS into a 2013 OS with a segment swap, the OS IDs have to be the same and if they were the same they'd already be the same year.

What diagnosis has led you to the conclusion that a ECM/TCM mismatch is the cause of your issue?

Does it work normal in P/R/N/D but never shifts out of first gear when driven? Or is it a 'stuck in first gear' thing, like all the time regardless of gear selection? Because if it's that second one, it is a mechanical issue in the trans.

[drewlawrence]

You can't turn a 2014 TCM OS into a 2013 OS with a segment swap, the OS IDs have to be the same and if they were the same they'd already be the same year.

What diagnosis has led you to the conclusion that a ECM/TCM mismatch is the cause of your issue?

Does it work normal in P/R/N/D but never shifts out of first gear when driven? Or is it a 'stuck in first gear' thing, like all the time regardless of gear selection? Because if it's that second one, it is a mechanical issue in the trans.

I do Have P/R/N/D but weather I am in Drive D6 or M it wont shift out of first. So I was thinking it was an issue in between the ECM and TCM. What other interlocks would stop the TCM from possibly shifting?

[blindsquirrel]

Oooooh, okay. So you have a TCM OS from what was an E92 DI truck, being used with a E38 ECM. Dunno if that works or not, not saying it does or doesn't. They do both use the same TCM hardware/service number.

[drewlawrence]

Might have to take it to gm I guess.
Thanks for the insite blindsquirell.

[blindsquirrel]

You can write-entire T42s and T43s without issue. You'd have to license the file, but then if you have it dealer-flashed you'd have to license it again anyway.

[drewlawrence]

Just an update. I flashed the tcm from the 2014 24270599 to the 2013 24265260 and everything is shifting. Thanks again blindsquirrel your the man.