02 stratus 2.4L trans is whinning and not shifting!

So this is whats going on and what i have done so far, when i bought the car it wasnt going into gears (NONE) so i changed the filter and fluid ATF+4 as required, it worked and now im having the same issue a month later. i changed the solenoid pack and the sensor right above the middle bolt for the pack( maybe the input?) and still nothing. i have called around to several trans shops and also some dealers and they all told me its the pump and needs a transmission rebuild, kinda weird how it worked before with just the filter and fluid change, was wondering if its something simple as resetting the TCM as i read on threads in the caravans with the same trans but slightly differnent issues, please help so i dont make an expensive decision if not needed, thanks.

Wouldn't hurt to reset, try dis-connecting the negative battery cable for a few minutes. Check engine light on, if so what are the codes? How does the fluid look when you check it? When you disconnect the battery cable the pcm may have to relearn how you drive so it may act funny for a while and make sure your battery and all connections and grounds are clean and tight. The whining noise has me worried that it may be time for a rebuild, is it still noisy now?

so i called around and asked a few mechanics what it sounds like, and everyone says its the PUMP, is a complete rebuild required or could i just replace the pump?,

02, probably the pump could be replaced but you know how people and shops are, they always recommend the most expensive route. Good luck to you.