I have a 95' sts and its been shifting hard from reverse to drive and all throughout the gears.. So hard that at full throttle it will leave a patch from 1 to 2nd gear... Took it to a local shop and they said they checked the connections and said it may or may not be the solenoid and it would be my risk to have them remove it and replace it.. Anyways about one out of 5 times you start the car it will shift fine and smooth. i noticed that the lesser the amount of fluid it has in the tranny the better it shifts too. This would suport what the shop said that when the code is present the trans runs at default which is maximum pressure.. therefore the lesser the level of fliud it would be closer to normal ... They said in realility it is not bad for the car to shift like this and would wait till it gives out completely.. What im asking for is if this is a cheap fix.. Do you have to remove the trans.. has anyone had a similar problem.. i am new to tthis link and have been reading other threads which are somewhat helpfful./ please respond if you know anything in regards to this... im a motor man ... hate transmissions.. thanks

Are you sure that fluid level is fine? Is it possible that it has too high level?
I found that checking of fluid level kinda tricky. It says, that "cold" level doesn't mean the level of not running engine. To check it "hot" engine should work at least 30 min or something like that.
I have problem with transaxle myself now, and when I check level at morning with not running engine I can't even see fluid at all. When transaxle is hot level looks normal, on a hot area of dumpstick.