02sierraz71_5.3

iTrader: (2)

This is what I surmise
There is no redundancy the allison transmission obviously has alot of other parameters that are used other than the GM tranns, I would guess that the allison has a different TCM aside from the PCM because it needs it and it is probably cost effective to make everything jive. I dont think GM manufacturers that transmission they might get it fully assembled and the TCM is made so it works with the PCM they bolt it up and go. The pcm is in charge of spark therefore I would be looking at it for all your spark being pulled during shifts and it looks like the TCM is mainly concerned with shift times and pressure. So change the pcm for TM spark retard and change the TCM for shift timing and pressures ( I would not change any of the shift timing/pressure settings in the PCM just the TCM)

It would be nice to hear from some of the tranns guys on this.

Whippled 496

iTrader: (4)

That all makes sense to me....sort of... I feel kind of dumb because the sole reason i set out today was to try and make some changes and record the results, but i got severely side tracked. I came across this thread from the EFILive forum and decided to see what it was about.

http://forum.efilive.com/showthread.php?t=3484

So, i found that i had a bunch of different PIDs that were able to be logged from the Allison TCM...aside from the ones from the PCM. Bad part is, they are not able to be scanned at the same time. For example, i cannot scan "GM.TRQENG_B" and "GM.kr" at the same time because of a conflict in the software, but it is supposed to be fixed in the new update in October. So, its a little tough to do if you dont have the PID selection available to you (and you wont unless you have an alllison tune). I also did a "knock" log to see where and when timing was being pulled. I did not get a chance to make adjustments to the tables and re-log to see what differences there were because i got so sidetracked with this other stuff. How accurate is the "torque" data being reported from the Allison tranny? Scan shows requested torque and demanded torque around 377lb/ft at different times, and i never really went above 70% TPS i dont think. Here is my "knock" log and my "allison" log. You will need to make PID adjustments accordingly in order follow the scan.

http://www.pasadenatownhall.com/allison_log.zip

http://www.pasadenatownhall.com/knock_log.zip

Whippled 496

iTrader: (4)

I just added the "dashpage" file and "PID" file for those scans. That should make it easier to open and follow.