Afaik, you are right; no... but...
Afaik, the manual/auto Ecm difference in those years is only that the auto Ecm has the TCC circuit.
You could put a switch & manually lock/unlock the TCC with it. Might be a pita for road driving.
I've read of guys doing that so they can lock the TCC on hill descents for better engine braking.
I think it was ebewley who mentioned it here before.
Hey Eric, what's it take to do this?
I'm curious too, I'd like to do it for road travel. I find some uphills I want to unlock the TCC but not have the pedal on the floor. If I let off it locks & I lose momentum. Sorry sounds sorta off topic. Maybe I'll start a post on it. (Mine's OBDII & the TCC circuit is different too.)