T42 4l70e to 4l80e segment swap

[Taz]

... 2007 trailblazer ss ... the trans os # is 24238660 ...

Yes sir, that is the OS I was referring to in post #3. There were no 4L80s that used that OS.

Given that, you have two primary options. Use the Frost adapter harness (which uses a 4L60/70 tune to operate a 4L80), and configure the 2007 TBSS 4L70 TCM tune to work correctly with the 4L80 (not your fault - you don't have access to some of the necessary parameters).

Or, transition to 2008 TBSS ECM & TCM tunes.

If memory serves ScarabEpic22 has ran his 2008 TBSS on 2007 TBSS tunes, and the other modules on the CAN Bus were OK with this.

I build Hot Rods and Customs, so I never have to be overly concerned about communication with additional modules (beyond the ECM & TCM). However, module communications will be at the heart of your issue.

A 2007 Silverado 4L80 TCM calibration will not communicate with your 2007 TBSS ECM - so that is out. A 2007 TBSS ECM will communicate with some earlier TCM calibrations, but a 2008 TBSS ECM will not. This means that the communication protocols are different between 2007 & 2008 TBSS ECMs.

Where I am going with all of this ? I you elect to try a 2008+ 4L80 TCM calibration, odds are you will need to use a 2008 TBSS ECM calibration, to establish proper communications.

[dmaxvaz1978]

would you have a 2008 4l80e tcm calibration i can use? i'm pretty sure i have a 2008 ecm out of a saab aero

[ScarabEpic22]

Got your vmail and text dmaxvaz, at my day job so I'll try to get some time to look through everything tonight. Havent had much time lately to post on here, but you wont be able to find that TCM OS for an 80E. You're probably going to have to go back to the 70E stock tune and correct it for the 80E or buy the swap kit from Joe at LeftCoast32.

And yes, I successfully ran an 07 TBSS ECM OS and 06 GTO TCM OS in my 2008 TBSS without any issues. With the availablity of some custom .cax work from Taz last year, I was able to go back to the stock 08 TBSS OSs and retain the feature the 06 GTO TCM provided.

[dmaxvaz1978]

ok, so i havent had any time to work on it this past wk, but i was wondering since the t42s have 3 sets of CAN bus links and the tbss only uses 2 of them; that what would happen if i jumped the ecm externally to the 3rd set? anybody think this would work? how else would this work on any tbss with someones special tcm?