2003 SXT Neon

Change both speed sensors in the trans and see if it shifts then..........

OR

Drive the car when it's 1st started and cold, see if it shifts thru the gears, then while in 4th gear floor it to see it kick down and then go into limp mode, which will be 2nd gear only and if so then you need to hope and get lucky it's one of the 2 speed sensors.
Most girls never seem to notice that the trans went into limp mode