Can EFI log data regarding my shifting problem?

I have an '01 Dmax that has had shifting issues before and after a rebuild. I get a double "bump" type of shift from 2-3 under easy acceleration and a HARD flare on the 2-3 when under a harder acceleration. I've had it to the Allison dealer 4 times, purchased an upgraded TCM/ECM (SoCal Diesel), have done a continuity check on the external tranny harness, replaced the leaky internal tranny harness, ohmed all the solenoids and can't find the problem. Someone mentioned getting an EFI unit to log the shift data so that someone (who?) could read it and determine what is going wrong? I'm not opposed to buy the EFI and getting a couple tunes IF usable data can be retrieved so that my truck is fixed!

bump for myself.

Let me explain further. Can EFI show me all the shifting parameters during the bad shift. I"m thinking things like rpm, defuel, input from various sensors, tranny pressures etc that would then allow someone to determine what is happening that causes the rough shift?

Just curious, is this in "normal" or "tow/haul" mode?

Hi,
Just in the normal mode. I actually haven't tried the tow/haul mode since I did the relearn after the tranny rebuild last Christmas. Perhaps I need to try that position also?

I think you can log more trans. data then you need. I have logged pressures, slip, and various other things. I am pretty sure that it would be a great tool for your diagnosis and other things. Provided your TCM is supported, I believe most if not all are supported. Anyone care to compile a list of Ally PIDs that can be logged to give him an idea? I even think you may be able to create custom stuff to mointor data you are cross referencing.

And there is no possible way this could be engine related like on the gassers right guys? I doubt it since it only happens in one gear.