T42 4l80E TBSS TCC Problems

[LSXGMC]

[FIXED] Reverted wiring at trans plug, and installed PCMofNC harness, re-flashed the old tune with modified tables and DTCs as directed by PCMofNC;
the swap works as intended.

It seems that, with the segment swap; the TCM was not getting any input from ECM for throttle position (?U0100 and U0101?), which resulted in no TCC unlock and no downshift relative to throttle input. The TCM would command downshifts and TCC unlocks relative to speed with no relation to throttle percentage. Upshifts, downshifts, and, TCC lock/unlock in the log would happen (no matter what the actual throttle position) at "25-31%" throttle. Gear indicator on the dash functions correctly now, as well. Maybe someone with more knowledge than I can explain, and possibly resolve the issue, without the need of reverting the segment swap and wiring using the PCMofNC harness.

I do want to shout out PCMofNC for being highly responsive and extremely fast with shipping. 10/10 transaction.

ALL INFORMATION BELOW WAS FROM TROUBLESHOOTING BEFORE THE ISSUE WAS RESOLVED

2006 TBSS Swap wiring and tuning using the sloppy wiki t42/80e writeup

Used OS posted below from an 07 2500 Suburban for TBSS swap. I am having problems with the converter locking as soon as the trans shifts into 3rd and staying locked through 4th. I maxed the apply parameter in third in all of the patterns and it still locks when it shifts into third. Used Bluecat's tool to change parameters, did not fix.

Not fixed - Getting a U0100 and u0101. Wiring was repinned according to the sloppy wiki writeup. No WOT downshift or TCC Unlock

[FIXED]Trans goes through all of the gears like the tune wants, just locks the converter. The parameters were copied over from the previous tune for the 60E and edited for the gear ratio difference. Never had a problem with controlling the lockup on the old transmission. Is there something there that I have enabled/disabled that I shouldnt for the 80E?

Still looking for solution for gear indicator on dash stuck in 1st.

Happy Freedom Day!

TBSS 4l80E no 3rd lock.hpt

[blindsquirrel]

I think you have to use the '07 Suburban TCM OS, not the '08 Express, with the GMT360 platforms. The Express works fine on the regular truck platforms but these are 'special'. As happens often Sloppy is sloppy with regards to specifics like this.

'07 Suburban has the benefit of being the same TCM OS (24235341) as the original TBSS.

[LSXGMC]

Thanks for the insight. I was curious whether the OS needed to match but I could not find any information to confirm. I will try this.

*Update* This worked. Gotta fix some things to get the converter to lock under 70mph, but it worked.

[LSXGMC]

I am still having an issue with my gear indicator. VCM scanner tells me the correct PRNDL position but my dash indicator is stuck in first. Also not kicking down or unlocking converter at WOT or high TPS %. I dont know how common it is, but the operating percentage from 0 to WOT is 28-83%


2006 TBSS 4L80E T42 24235341 V3 BlueCat.hpt

[blindsquirrel]

You can try segment swapping, one segment at a time from your original 60E file. Hopefully the part that controls comms to the IPC does not also contain the 80E-specific bits. Segment swap ONE segment and then 'copy all differences' - this will retain the settings from the Suburban file but use the underlying OS-type code from the TBSS. If that doesn't fix it go back to the all-Suburban file and swap in the next segment in the list and try again.

[LSXGMC]

Thank you sir for your assistance. I wish I would have done more research beforehand, it seems the 06 TBSS T42 is complicated. I tried segment swapping and it led to other issues and I dont have enough experience to be confident that I was doing it correctly. I did find that the trans final drive was set to 4.10 instead of 1.0. Probably unrelated to the no downshift/tcc release at WOT. I will probably just have to take it to my tuner, or move the pins back and buy the LC32 kit.

[LSXGMC]

FWIW Here is my OG tune for the old transmission if anyone wants to take a look and see if they can see anything that I cannot.

2006 TBSS LS2.hpt

[LSXGMC]

Issue resolved. See initial post.