So how do I get a data stream from the factory GM TCU?

My brother just test drove this with the scan tool attached and sent me this:
Drove the Alumalite. Trans temp: 170. Locked and unlocked...

I am out of the country right now, but my nephew says he can test drive it with the scan tool. I am not sure what it can tell us other than rudimentary error codes.

Because the transmission works...

I have a OBD1 1992 P30 Chevrolet chassis with the 454/4L80e combo.

Unfortunately, I can't remember exactly how/when it started, but it has a problem that happens when it kicks down from 4th to...

Hi all... This is my first post here.
I am looking for a solution for my P30 (1-ton) motorhome with the 4L80e that I just converted to a 2-speed rear end.

I have two issues:
1) old problem...