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I just bought a 2007 TBSS with a 4L80e swap already done. It has a PCM of NC harness and the TCM was already tuned going by their instructions. Trans is in limp mode. I do not care to repin the harness for a 4L80e if I can find the correct TCM. I am assuming I need to find a TCM from a 2007 Express/Savannah for this to work correctly. Any and all info is appreciated.
Ok what codes are showing up? Limp mode for the trans can be caused by a handful of things, including issues with the ECM side.
If it's truly an issue with the TCM OS and 80E swap, you have 2 options:
1. Use the PCMofNC harness and tune per their instructions.
2. Remove PCMofNC harness and go back to stock TBSS wiring. Then repin a few pins so the trans harness matches that of an Express van and segment swap the TCM with an Express file (available on the forum and in the HPT repo). You'll need to go through and update the gears, tire size, shift points, etc as they won't be set up for the TBSS after the segment swap. Use the segment swap feature so you don't have to license the Express file.
The TCM OS has to match what you already have. Since you did not post a file...
The TBSS sample files I have here have 24238660 for '07, and 24239927 for '08. I did not check TIS to see if either of those are the most up to date, but you can.
Here are the T42/80E files commonly used for segment swaps:
Attachment 104478
Attachment 104479
Quote:
Originally Posted by erks
Start with basics. Why is it in limp mode?
Just what I needed. Thanks for your help man!Quote:
Originally Posted by blindsquirrel
I have an 07 TBSS E67 T42 setup, ive licensed the file and have the same 07 suburban file you posted, for some reason when i open the suburban file as a compare the segment swapper is still greyed out and wont let me switch the TCM files. do you have any insight for this issue? as far as i know this should work without issue....Quote:
Originally Posted by blindsquirrel
The TCM OS ID has to be the same between both files before the segment swapper will work. If you ask questions like this and don't post the file, it's just guessing.
Please note that was a comment from 3 years ago - there is a 'special' file that's been found to be the right one for this swap in a GMT360, it's from a Tahoe and it has one segment different than the Suburban file. Reportedly, there are PRNDL display issues with the Suburban file.
edit: Oh, right, you're asking about a 2007. No dice, those do not have any compatible 4L80E files to swap from (afaik the TBSS OS was not used on anything else other than a TBSS and TBSS never came with 4L80). Use the relay harness and get on with the rest of your life.
Would I not be able to just license another file and write TCM only over top of the tbss file?
You don't segment swap T42's or anything GEN 4+ for that matter. What people do is fine a T42 file that will get along with the OS in the ECM. I'm fairly certain there is a express van 4l80 T42 that will work for this application 07 TBSS. Which one.. I don't remember. but you can try each until it works.
I made a 4l60-4l80 swap harness precisely for this reason.. I didn't have the time to look for each obscure setup that rolled in and a OEM 4l80 segment or T42 that will jive with everything else. And while yours is not.. there are several applications with no 4l80 segment swap or T42 options.