transmission does not shift gears

1993 dodge grand caravan 3.3 liter engine a604 transmission
transmission does not shift gears, i test the computer and it dont detect the problem,but the problem is i do not know for sure and i dont have another compuert to check it and i dont have any information about probing the pins on the computer,i need help urgently please!!
the computer tells the solenoids to shift the gears in the car but the car does not shift gears
i have tested everything except the computer

I have a 93 Plymouth Voyageur 3.3L 6cylinder, sounds like I have the same problem... I can't hold 60 km/h because the tranny won't switch gears - kinda sounds like its doesn't know if it wants to go up or down.. I was told by some guy in a gas station that these vans are known for this problem and need to have the transmission flushed regularly..? Haven't tried it yet but will keep you posted if I come up with anything that works.

I had the same problem w/ my 1994 grand voyager...the problem is the speed sensor in the transmission

There is 2 sensors,,,turbine speed sensor,,,,,vehicle speed sensor....If they are not working ,,,the computer interpits signal loss as "engine not running" or vehicle not moving,,,,,,ER,,,,no need to shift,,,,,,...Can't imagine what a
tranny flush will do to FIX this problem???????????except lighten your wallet of 100 bucks!!!!!!!!!! send the $$$$$ to me ,,,I'm broke!!!!!!!!!