2003 Allison tcm OS for 8.1l

[Frebo74]

Hi,
Do anyone have a stock tcm file with OS for 8,1l GM? I have swapped in a Ally on my 8.1 silverado and need to Swap OS to Get communicatin to the pcm. Hope anyone can help..

BR
Fredrik

[Cougar281]

If no one else has it handy, I should be able to get it if you provide a VIN, but it'll take me a minute because I'll need to reconfigure my AL5 bench harness connector for my new bench harness to get it.

[Frebo74]

Hi,
I think I need OS 15163073. I have OS 15184109 today and it will not talk to the ECM

The VIN nr is 1GCHK23G63F136524.

[Cougar281]

The only OS available for that VIN is the one you have.

What transmission did your vehicle have before? I thought all 8.1's came with the Allison?

[Frebo74]

This vehicle was an silverado with 6.0l engine and 4L80E, I have swapped the engines from 6.0l to 8.1l and now I have swapped 4L80E to Allison. The Allison comes from a LB7 Duramax, so therefor I need to Swap the OS to get the TSM to comunicate with the 8.1l ECM

[Cougar281]

Is that VIN for your truck that came with the 6.0 & 4L80?

[Frebo74]

No, that was a VIN form a car that have 8.1l and allison. But I have today flashed the TCM with an OS 15172883 from VIN number 1GCJC39G42E198682 with Techline Connect. It worked for a few miles, but after a wild it get into limp home mode. do you know if the OS i use now is correkt for Green/Blue ECM?

[Cougar281]

Ahh... Ok. Well, here is the tune that comes up for that VIN. It's the same OS as you have, but it could be a different calibration.

OS: 15184109
Trans Cal: 15187101


24998

[Cougar281]

I should add that I missed your bit about the other VIN... the VIN 1GCJC39G42E198682 is from a 2002 truck. I can't speak to the gasser side with real authority, but on the Duramax side, a cal from a 2001-2002 truck will work just fine with a 2003-2005 LB7/LLY truck (I and many others ran 2001 TCM calibrations on newer trucks to make the TCM 'dumber', my truck being a 2004, until I swapped it over to a LBZ drivetrain). Gassers might be different. But the tune I posted was GM Stock for the 1GCHK23G63F136524 VIN, as well as other 2003 8.1 trucks I found on the interwebz.

[joecar]

Interesting two way swap, let us know how it goes :)