I have an odd problem with my 4L80e. At WOT the 1-2 hits as programmed (6500rpm), then the 2-3 is always right away at about 4800rpm. I dont know about 3-4 yet. This will happen EVEN IF the shifter is held in manual 2nd, or if the TCM is commanded to hold second. If you hold the shifter in 2nd and just drive normally it will hold second gear til the rev limiter.

Trans is a 2006 with Transgo shift kit. Works perfectly otherwise. PCM. is stock 2010 LC9 with T42 TCM.

Any ideas?

 

Nobody?

 

unify the shift tables using the BlueCat Trans Tool

make sure the VSS pulse per mile is correct for your gears and tire size

i have very little experience with the t42 but I now it needs can data from the e38, it may be that something disabled to make the swap easy has unintentionally sending funky data to the TCM

 

What Doug said. I researched the hell out of it trying to figure it out...so you are cheating getting it from Doug! I think I have it resolved in mine but I haven't verified it yet. Same problem only the bad way as in not shifting until the rev limiter.