2008 Denali 6l80e TCM replacement trans questions

[SUTTERERMAN85]

So I picked up a 08 Denali and it needs a trans. Can I do a read entire and then do a write entire to force the original OS and VIN to the new trans since the TCM is bolted to the valve body? Or is this something that has to be done with a TechII? I have read that HPT 3.X you cant but an older version it was possible to change VIN? My other option would be to swap the TCM from the original trans to the new one and it should work as well? This is the first one of these I have messed with. Thanks in advance.

Nick

[relicdew]

Nick,

If you get another 2008 or even 2009 trans you should be able to do a write entire on the trans only. With 3.x software you can skip writing to the ECM and Write Entire to TCM. I would do a read first though once you get the new TCM just in case you have an issue writing and need to recover.

[SUTTERERMAN85]

So I should do a read entire and lisc the stock ECM and TCM, then with the new trans installed do another read entire and not lisc that unless I have to? But you are saying that if its the right year I "should" be able to do a write entire on the TCM only and it will change the vin and all to match?

[SUTTERERMAN85]

Update for anyone else that needs to do this. I read and licensed the original e38 and t43. Installed the new to me trans, another read entire. Turned out to be the same t43 os. I then did a write entire to the t43 with the original tune. All is well. Not sure if it would work if the t43 had a different os from a different year/car.

[Oleblu]

Good to know this as the shop I work in sent a truck to a dealer a few weeks back. this was a trans install on a 2014 using the t43 controller. I was curious then if I could possibly do a read/write entire to the new tcm.