6Hp26 harsh 2-1 downshift - possible solution (at least one of them)

[Doru]

First a big THANK YOU to Fmugur - he's a member of this forum.
He owned a 2000 4.4 and he has a 2006 4.8 and another 4.4 with the N62 engine, so he did also a few experiments, and some we did together.
Last week he called me with a new find concerning the transmission. He told me that the ASC module, which is related to wheel speed sensors AND transmission has also to be updated, for the transmission to work flawlessly. And so he did this to his 4.4, without changing ATF - it worked. My transmission worked great, but for the heck of it I also changed the software for the ASC which was big time outdated. I had no idea, until SSS Progman showed the version I had and the version it will replace it with.
After re-programming the ASC, the shifts were even smoother. Up to that point I thought I had a flawless transmission, but after the update, the truck is extraordinary smooth, better than a Cadillac, no exaggeration. Extremely happy.

So if you consider servicing the transmission, after changing ATF, seals, etc, update and re-flash the mechatronics module, followed by updating the software for the ASC module. The results are stunning.

the ASC updating takes about 1/2 hour with SSS progman.