Lets see who knows about transmissions.

I have a 92-2.0L non turbo auto transmission. We all know that trannys are complicated. I've gotten to that point now. While accelerating, my tranny shifted from first to neutral. OK so my fluid might be low, not the case here. I can only say it will only shift from park to neutral, no matter what the shifter is on. It does lock in park. The OD doesn't work but I know that is an unrelated but common problem. To answer all the dumb questions...the torque converter is still connected, the fluid is at the proper level, all wires are connected. I already figured it is not a major mechanical issue. My question actually is though, which sensors would tell it to shift or which valve gets the fluid moving to shift the gears? I was told to check the modulator valve but I concluded I don't have one. Then I was told to replace the kickdown servo. Anyone know what that thing does? Any help is appreciated.
-Thank you
Jason

they are called shifts seloniods which shift the car in gear.they are located if u take the pan off and take the filter and body something cant remember the name sorry. the shift selonoids are on the opposite side. they are usually black and u have 3 of them with wires. they could be blocked or a wire disconnected or even worse broken(they cost approx 250) remember if u take it off take all the bolts marked 10? and if u do it and know nothing u should get the whole tranny rebuilt with new clutches and steel even possibly a band if its bad.

the kick down servo is located in the front of the tranny its in place with a circle plastic cap with a wire comming out

anyone know how to check ecu codes...I did what this guy says on this site (http://www.plymouthlaser.com/tcucodes.htm) but they are coming up the same as my engine codes, but I know why my engine codes are coming up.

scan tool or have someone do it for you, it's free at certain auto stores.

u mean valve body ?

ACTUALLY...I really meant the transmission control unit...I just realized I put ecu in there but I know how to check that. I need to see if I can figure out whats wrong with my transmission. Let me just ask the question again. Anyone know how to check the TCU codes?

yeah that was it valve body lol. I have a special guy who checks the codes i dont mess with that