Hi there. I have a 2005 Trailblazer (RWD not an SS) Gen 4 LH6 5.3 - I want to change the 4L60 to the 4L80e.
I have the E40 PCM and the T42 TCM. I do not know which OS either have, though I plan to get HP Tuners at some point.
I've read countless threads here and on HP Tuners forums... but the last posts are from a few years ago and there seems to be 2 main methods of making this work.
I have read about buying a harness from one of several companies, and I have read about just re-pinning the original harness.
I have read about segment swaps between matching OS TCM's, and just swapping with a 4l80e T42 TCM, and every combination of the above.
I have even read recently that no one has actually gotten this combination to work, but also read that member slow67 was very knowledgeable on the topic, however, he hasn't posted here in almost 4 years.
Has any proven, yet simple solution come to light? Please talk to me like I'm 10 years old and explain my options LoL Thanks in advance!

 

I've attempted this previously with GTO's that we swapped 4L80E's in to... I have NEVER been successful doing the tuning side of it.. The repinning of the harness is easy.. However any time I've attempted to flash the TCM with the 80E programming, it ends up BRICKING the PCM. So, I've ruined 3 perfectly good PCM's in the past attempting this and have never gotten a good answer as to how to do it right. In the end, I ended up sending those vehicles out to a local tuner who then was able to figure it out and get it working.. however it was $600 JUST TO GET THE TRANSMISSION TO SHIFT CORRECTLY and did not include any other tuning... SO... Can it be done? Yes. Is it commonly available knowledge how to do it.. Not in my experience. Many people say that you can just flash the TCM with the 80E programming but I've never been able to get that to work.. I'm subbed to this post to see if a clear concise answer is posted.

 

Now that I've slept, I'm beginning to wonder if the Trailblazer SS TCM or PCM is somehow 'special' along with the GTO, because almost every post I've ever read seems to involve an '06 TBSS or GTO for the swap?
Also it seems the 80e front speed sensor must be hooked up too, but I have never seen which pins on the E40 they hook up to ( i think it's pins 22&23 on the E38 PCM).

 

I did read that the T42 and E40 don't have to have matching vin numbers to play nice. Couldn't a person just use a T42 from a 4L80e vehicle so there's no flashing?

 

A T42 is a slave module, same T42 can control 4l65, 4l70 or a 4l80. We have done several TBSS and GTO's with 4l80's so it can defiantly be done.

 

How much would you charge to share the process? Currently there's 2 people in this post who would really like to know, and I'm willing to pay if that's what you want.

 

Doing a 4l80 swap in a tbss or gto isnt any different than doing one in silverado same theory and process essentially. There are several companies that sell 60-80 swap harness and sell programming services for the swap. You just need to decide which way you want to go and search for companies offering that way.

 

It looks like if I had a 2006 Trailblazer SS I'd be in better shape. 2005 is a big PIA. Leftcoast32 says no way with a 2005 with their stuff because all their R&D went into 2006-2007. Waiting to hear back from PCM of NC. :/

 

If only that were true... It is COMPLETELY different than doing a truck. If it were the same as doing a segment swap on a Silverado, there would not be so many people having issues accomplishing it! Keep in mind, the T-blazer SS and the GTO NEVER had a 4L80E installed from the factory. So... Yes, I know it can be made to work, but NO, it is NOT as simple as some people on this post are making it out to be (not just you mini). I've done HUNDREDS of segment swaps on various vehicles through the years but have KILLED multiple PCM's in GTO's and T-blazers trying to do what I do with Silverados on them. There is something drastically different about those specific PCM/TCM combos that makes it more difficult than a Silverado.. Not impossible.. But more difficult.. Hence the reason for the OP's post.. If you do a search you will see that lots of people have had problems attempting this.. And.... If it is so simple.. Please tell me what we are doing wrong.. I can seg swap a Silverado in under 10 minutes start to finish and it will work perfectly every time.. However.......... GTO's NO! Not gonna happen as easily as a Silverado.. Maybe there is 1 extra step that I'm not doing... maybe there's more than 1... but I can assure you it is NOT identical to seg swapping a silvy... If it were that simple, I'd not be posting here now.

In the past when I attempted this, I could flash just the TCM and the trans would run and shift, but it would not run CORRECTLY. Meaning it would lock up the TCC almost the instant the car started rolling.. .Various attempts to fix that issue resulted in a BRICKED PCM. Then, on the next one, I flashed the TCM and the PCM with a different operating system (one that WAS paired with a 4L80E from the factory) and then the GTO WOULD NOT START requiring me to flash the original OS and TUNE back onto the car to get it to start.. Then after a few more attempts-BRICKED PCM.Then on a T-blazer... this could take a while.. My experience has been that flashing these specific vehicles IS different than all other years/models of GM/GMC vehicles. If I'm wrong... Tell me what I'm doing wrong.. Or, let's let the OP brick his PCM and then we can all have a discussion about the right way to do it.. That seems to be how I learn everything with HP Tuners-AFTER I brick a PCM then someone pipes up and says :"oh you gotta do it this way"...

 

I would have loved to 'easily' have used all the original low mile electronics in the Trailblazer I have with just a harness and some tuning. GM had to go and mess around with stuff making everything difficult lol. I was aware that I would have had to swap to a 58 tooth reluctor and different cam gear, but the engine will be built anyway so, no big deal.
In my case I can just scrap that plan and go standalone because it's going in a project car. I actually just had a 2001 Suburban with DBW fall into my lap for just some labor. So I'll have all the gen 3 wiring and stuff from THAT vehicle instead. It's gonna be a whole heck of a lot easier to get a 4L80e behind those factory electronics! But just to make things interesting, I have to look into an X-Link because I want to keep the intake and larger throttle body from the LH6 if possible.
Anyhoo, after days of research and hours of reading and videos, this is too difficult of a path for me to attempt. Even if someone gave me step by step instructions guaranteed to work, it's still so much hassle. I have a computer and harness now by a miracle, so I'll go the easy route

 

I think what you are doing is SMART. Avoid the drama.

 

Without knowing exactly what you were flashing into these when you bricked them I am going to assume based off what we have seen others do wrong. I also dont know your knowledge level on this so forgive me if I post some basic stuff, just trying to explain it. The T42 is not the issue, it can flashed to work with 4l60e, 4l65e, 4l70e and 4l80e. On the ecm side, this where most people mess up. On E38, E40, and E67 everything is based off the service number on what you flash into them and have them work correctly, the ecm's look identical and have to be identified off the service number. They also have to be flashed with SPS in order to flash all 8 segments when brand new or when changing from a car to a truck calibration. Each service number ECM is only compatible with certain OS's, flashing the wrong OS into any of them will brick them almost everytime. If it doesnt brick it it usually throws a P0606 code or has crazy DBW issues but will run. Thats the short and dirty basics of it, it would take pages to go into every detail of making them work.

 

"No big deal. In my case I can just scrap that plan and go standalone because it's going in a project car."
Holley Terminator X Max, and be done with it.

 

Oh to be able to afford a Terminator *sigh*

 

Minytrker, is there a list somewhere that tells what OS can go into which service number for the E38/40/67 ecu’s?
Maybe include gas pedals too.

I rarely tune these, but that would sure be handy for helping folks out.

Ron

 

This is a pretty good list.

 

Thanks mini for that information. It proves beyond any reasonable doubt that there is something VERY special about the GTO's and the T-blazers and IMO-the average tuner-like me-has NO BUSINESS attempting to flash them to get them to work with 4L80E swaps. I don't know what an "SPS" is-but if its something other than HP Tuners-I don't have it. This post should serve as a warning for those who have these specific vehicles-BE FOREWARNED! The problem I was having is that I could easily flash the T42 with the correct programming.. However, there is some type of hand-shake arrangement between the TCM and the PCM that goes wonky when you flash the T42 in these vehicles.. At that point the communciations between the PCM and TCM becomes corrupted and it simply will NOT WORK that way... Ive been told that the PCM, and the TCM must be flashed together as a unit in order for them to continue the hand-shake arrangement and have proper communications between the 2.

I think the easiest route to do these conversions-on the T-blazer SS and the GTO, is to look up the service # on the PCM, and then find another operating system that came from the factory that was paired with a 4L80e that is compatible with your service #.. THANK YOU Minitryker for that information!!! Then, if we knew which SERVICE #'s were capable of working with WHICH operating systems, we could then flash both the TCM and the PCM together at the same time. That would be the only way to work around this problem.. Well that and an understanding of what "SPS? is, and if we, the end user at-home-tuner, have the capability to flash that.

Until more is known about doing these swaps I will stay far the "F" away from attempting to 4L80E swap these vehicles. The OP was WISE to ask up front about this as he has probably saved himself a bunch of time, money, and frustration. I think the OP mentioned swapping to an older PCM/TCM arrangement thereby avoiding all of the drama. Very smart on his part.

 

SPS was the GM flashing program but it just changed to Techline Connect. Its a subscription based program you use for factory programming (has to be done on brand new E38, E40, E67, E92 etc) with a J2534 programming tool. It also what you use to get the latest calibrations for any module in a vehicle. Its the only way to flash all the segments in an ECM, tuning software only flashes 6 of the 8.

 

I've never had a problem making a T42 control a 4L80 in a GTO or TBSS with the correct OS but if for some reason it's not working with whatever you are doing why not just run the original 4L60 OS and use an adapter harness that flips the solenoid operation? I believe PCM of NC sells one and maybe one other company as well.

 

Thanks, saved in my tuning reference files!

Ron