1998 Plymouth Voyager Wont shift out of first

Hi Mike, Seems confusing and it takes hours of training for theory, nevermind fixing it when something goes wrong. 3 computers share information, actually more but lets say 3, Transmission, powertrain, and body computer modules. TCM,BCM,PCM. Your TCM has inputs from the trans and the computers via sensors and wiring. The TCM controls the various solenoids to allow hydraulic fluid to apply different internal mechanisms. The solenoids are housed in a black covered pack in the front left part of the transmission.
If the solenoid does not respond the TCM has preset parameters that if not met store a fault code in the TCM. When a code such as yours is stored the computer tried to move the solenoid but got an improper return. This could be a bad solenoid or wiring(circuit). I hate to say it but the dealer should have information found on their scanning computer and they use a large diagnostic book to start diagnostics. The only thing you might do is check the fluid and make sure there are no obvious wiring conditions like an open or short circuit. This code was a solenoid pack code and replacing it without doing diagnostics could mean doing it again. It may be something internal also, and the PCM has codes also that sometimes are common to the problem. You could try replacing the solenoid pack but I don't think I would only because of your high mileage. Fluid thats burned or low is a sign it needs more than just a solenoid pack. Why not read the section on how your transmission works and this limp-in mode and why it occurs. The first thing I would do is smell and check the fluid.
I hope this helps you somewhat decide on whether you want to try another solenoid pack or not, if the dealer replaced the computer recently it may be covered, as the TCM controls these solenoids.