Non-GM 4th Gen TCM calibrations

[Cougar281]

I'm probably going to try and help a local Alli tech out with his personal truck. He has a Dodge/Cummins with a 6 speed Allison behind it. He's been trying different Allison Calibrations, and has found one that seems to work, EXCEPT when he puts it into 4Lo. The TCM then limps because the 4Lo ratio isn't what it's expecting, and Allison won't give him a calibration with the right ratio because it's "GM Proprietary". Will I be able to read a non-GM 4th Gen TCM (A40 or A50) that uses J1939 for programming or will EFILive go :wtf1: TILT, OR will a TCM that uses J1939 also accept read/write requests via the GMLAN pins?

The 3rd Gens where easy; they all got programmed over the J1850 bus. 4th Gen not so much...

[Cougar281]

Any thoughts Ross?

[GMPX]

I don't really know as I've never dealt with any non GM TCM's.
It is possible that the TCM he has does not use standard GM commands for reading / programming in which case it of course won't work. I can't see any harm in trying!
I thought that Allison shops had access to software that would allow them to alter calibrations for custom jobs?

Cheers,
Ross

[Cougar281]

I don't really know as I've never dealt with any non GM TCM's.
It is possible that the TCM he has does not use standard GM commands for reading / programming in which case it of course won't work. I can't see any harm in trying!
I thought that Allison shops had access to software that would allow them to alter calibrations for custom jobs?

Cheers,
Ross

From what he told me, they can only program calibrations that Allison sends them, and Allison won't give him the Dyno cal he's running with the proper 4Lo gear ratio, which was why I suggested we look into checking it out with EFILive. I'll have to give it a shot when I meet up with him.

[Brayden]

I sell these controllers with custom calibrations in them... locked of course. But it's possible. They're better than dyno cals also, those don't really shift too well.

Brayden