I have a 94 Caravan w/  the 3.0L V6, and the A604/41TE tranny.It has
94k miles on the van. I recently replaced my TCM with one that has the
latest flash in it. (I picked it up from a friend of mine who runs a
local tranny shop.) I replaced my original TCM with this one, and had
a quick relearn and the pinion factor set for my van. Everything was
fine.

A few weeks later, the tranny decides that it doesn't want to go into
4th(OD) under 50MPH, where it would before. When it starts to act like
this, it seems like it is in "3" and delays shifts.

Under advice from the tranny guy, I replaced the TCM with the
original. Relearned and I am on the way. A few weeks later, it does it
again. Same issue. However, something new has popped up. The tranny
seems to want to have a hair trigger in the kickdown. You can be going
along at 30MPH, and barely touch the throttle, and it would downshift.

I bought myself a Snap On MT2500 scantool (been wanting one anyway..
early birthday present). I pulled the CVI's...

LR - 53
OD - 79
24 - 36
UD - 41

No codes are present. No codes show up while driving. I recently
replaced the TPS as the old one was kinda flakey.

The tranny has good ATF+3 in it. The engine RPM vs. turbine RPM is not
far off.. maybe a +/- 50RPM difference.

I read another post about a problem with a A604 that was going into
limp mode, and it was linked to the zener diode in the a/c harness
causing the problem. I am going to replace that here in the next day
or so just as cheap insurance.

Any help appreciated......