T42 4l70e to 4l80e segment swap

[dmaxvaz1978]

so, i had the pcmforless/tuned by frost trans conversion harness and did not like the fact that there is no iss, so i pulled the harness off, and re-pinned my stock harness plug and added an external iss wires and plug. My question is: do i need to find a 4l80e tune with the same os # as what my 4l70e tune os to do a segment swap and have it work?

[joecar]

Yes.

And the harness needs a minor repinning.

[Taz]

... My question is: do i need to find a 4l80e tune with the same os # as what my 4l70e tune os to do a segment swap and have it work? ...

It is always beneficial to post your tunes (ECM & TCM), to assist with obtaining a specific answer to your question, rather than a generalized response.

If this question is regarding the 2007 TBSS in your signature, these used a unique TCM OS, and there is no corresponding 4L80 calibration.

[dmaxvaz1978]

It is always beneficial to post your tunes (ECM & TCM), to assist with obtaining a specific answer to your question, rather than a generalized response.

If this question is regarding the 2007 TBSS in your signature, these used a unique TCM OS, and there is no corresponding 4L80 calibration.

are you saying i cant get a 4l80e tune to do this? i wired the harness at the tcm and at the trans like a 4l80e. I tried to flash a 4l80e tune in it last night, and it didnt work. i need to look up the os and post it. i am a little green when its about anything computers. from what i have read, a T42 tcm from a 2008 6.0/4l80e van should work

[joecar]

Taz is saying that there is no 4L80E file for your context.

[Taz]

are you saying i cant get a 4l80e tune to do this? i wired the harness at the tcm and at the trans like a 4l80e. I tried to flash a 4l80e tune in it last night, and it didnt work. i need to look up the os and post it. i am a little green when its about anything computers. from what i have read, a T42 tcm from a 2008 6.0/4l80e van should work

When you come to this Forum asking for assistance, the onus is on you to provide any / all information necessary for correct answers to be formulated.

You were directed to post your tune files - which you have not done.

My answer in post #3 had to employ the "crystal ball" approach - guessing what vehicle you were referencing by looking at those listed in your signature.

Also, my answer in post #3 was in response to YOUR question - regarding a segment swap.

You are now asking about using a completely different OS, from a completely different vehicle - which is a completely different question.

Post your tunes ... describe the vehicle these questions reference ... and perhaps we can provide you with some reasonable options.

Just a little tip regarding Forum decorum ... if getting the necessary information from a posting person becomes like pulling teeth, then odds are that person will not get much support.

[dmaxvaz1978]

When you come to this Forum asking for assistance, the onus is on you to provide any / all information necessary for correct answers to be formulated.

You were directed to post your tune files - which you have not done.

My answer in post #3 had to employ the "crystal ball" approach - guessing what vehicle you were referencing by looking at those listed in your signature.

Also, my answer in post #3 was in response to YOUR question - regarding a segment swap.

You are now asking about using a completely different OS, from a completely different vehicle - which is a completely different question.

Post your tunes ... describe the vehicle these questions reference ... and perhaps we can provide you with some reasonable options.

Just a little tip regarding Forum decorum ... if getting the necessary information from a posting person becomes like pulling teeth, then odds are that person will not get much support.

i have the tunes on my brother's computer, and have yet to get him to post them up. sorry about my limited knowlege on this stuff. taz, if you think you can help me, call me at 248 459 9263, i would like to talk to you on the phone. i would compensate you with $$ for your help. i can email you the tunes

[Taz]

No worries ... post the tunes when you can ... you could however, describe the vehicle and list any modifications.

I would rather you kept going (appropriately) with this thread ... if you have these questions, so will others at some point.

I barely have time to post these days, phone calls are not an option.

Advice will always be free of charge - that is why Forums like this exist. For specialized tuning services (that no one else / or very few people could offer) I had to draw a line in the sand awhile back, and start charging a nominal fee.

[dmaxvaz1978]

2007 trailblazer ss 390ci stroker, 4l80e, 80mm turbo, runs on e85. SD tuned, 127lb injectors. e67 ecm/t42 tcm. was running trans harness with relays and only oss sensor, and ran it with 4l70e tune (some codes removed). the trans really never ran right with the relay type harness. the speedo would drop out, it would not shift out of 1st gear after a burnout, and would have no converter lockup on the hwy after driveing it more than 2 min. the the trans os # is 24238660.

[dmaxvaz1978]

Here is the modified 4l70e tune with 80e ratios and no ISS input, using the frost/pcm4less harness. Thanks again

[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?