4L80E swap in 2007 GMT900 - E38/T42 TCM OS: 24239036

I am doing a 4L80E swap in my 2007 Silverado NNBS. From another thread I found the "2008 Express Van with 4.8L" comes stock with the 4L80E so I downloaded that file from the repository. Inside the tune I find the TCM OS ID: 24239927. My TCM is OS ID 24239036. Using the compare log function I simply did a "copy over all differences" on the transmission tree.

My question is, will this work? Assuming I re-pin the trans connector and add the ISS sensor wiring, is there any reason that I'd need to write the entire T42 OS from the newer Express van OS ?

Edit: My ECM OS ID: 12614088

HIghly unlikely that alone will do the trick.

Say theres 8000 tables in the TCM, you probably changed 200-300 of them, the other 7800 or so are still the same.

I had forgotten that there are tables in the ECM and TCM OS that are not exposed in the software, thanks for pointing that out!

I will have to load the beta software, license the 2008 Express van tune, and write the TCM only. Anybody know if my ECM OS 12614088 would be compatible to communicate with the TCM OS 24239927? I'm thinking I'll try it but just dont want to damage my new 4L80.:pray:

bump

Sorry I never came back to give some closure on this so here goes...

I ended up downloading that (2008 Express Van 4.8L) tune from the tune repository with TCM OS ID: 24239927. As a precautionary step I purchased a new blank TCM off of ebay so that I could put my stock TCM aside for back-out/recovery purposes. (This precautionary measure ended up being unnecessary but I chalked it up to being part of the learning process...$75). Below are the steps Followed to achieve mating my E38(4.8L tune) with the T42(4L80E tune).

I used the beta 2.25 software at the time, but the same can be done with 3.0 or later now that the ECM and TCM write routines can be invoked separately.
1.) Read Entire (both ECM + TCM) of your current setup and save it to a safe place.
2.) Write Entire (both ECM + TCM) of the 2008 Express Van 4.8L tune. (requires licensing of the tune -- 2 credits)
3.) Write Entire (ECM only) of the original tune.
4.) Modify your trans tables for proper gear ratio (shift points, etc) and adjust traction control stuff as desired then you can write calibration only for both ECM and TCM.

There are other ways to do it but now that the software supports writing one or the other it makes this super simple. The other thing to note is that this did cost me 2 credits since I had to license the Express Van tune in order to take the TCM portion of it. If you have a 4L80E T42 TCM handy or can borrow one from a buddy, this would save you the credits.

Im bringing this back from the dead. I swapped a 80 into my 07 nnbs. Paid the 2 credits and loaded the express van tune(ecm/tcm) that redheartbeat posted in the tune repository. It loaded the van tune with no issues. Then when trying to reload the original ecm tune it is telling me to license it. Well of coarse I have all ready licensed it 2 times now(original tune and then upgrading to 2 bar os) We where not using the newest version of 3.0. We updated it last night going to try again tonight.

My question is. I have an older version of hp tuners on my laptop(not the one that has been tuning the truck). Is there any way to do a write only ecm with an older version?

There is no option for writing TCM only in the old 2.4 version but from I'm told it can be done by performing the write and pulling out the USB cord at just the right time (between ecm and tcm write). I never tried it but supposedly it works since the ECM and TCM are physically separate and are written to sequentially. Again, I never tried it so do this at your own risk.

In any event, I'd just upgrade the software and bring your licenses with you. That is one nice thing about the software licensing schema

I have the newest 3.0. That's the problem. My truck has been licensed for a few years. Then I decided to install a lsa supercharger and upgrade to a 2 bar os. All was good for the last 2 months. Getting maf dialed in and ve. Then decided to swap the 4l60 for a 80. Then I followed your lead and licensed the express van file so that I could use the tcm file. After doing a write entire of the van file. Now it is asking me to license the original ecm tune.

Anyone able to help a noob?
2007(1/2) NNBS 1500 2x4 reg cab
Did the 4l80e upgrade.
Anyone have the harness Pinout?
Also, this is my first time using any tuning software. Can someone tell me how to get the OS for an 80?

I dug up my notes from the swap. Should be some useful info in there...
Attachment 87909