my minivan is having a problem?

Well if your engine rpms are going up and there's no movement that means your tranny has kicked the bucket and likely needs a rebuild. If your speed sensor went bad then the speedometer wouldn't work. Most likely it was caused by changing the tranny fluid so late in mileage. Don't go nuts though its cheaper to just get another transmission from the junkyard and have it put in.

is the engine light on? and have you checked your transmission fluid? you need to look at the fluid first, and see if it looks or smells burnt or if there is debris on the stick, speed sensors will put the car into "limp-in"mode which basically just means it wont shift up out of low gear.if it completely quits moving it is probably not a sensor, after it quit moving and then started moving again it is probably not the torque converter, because usually when they go bad the car wont go again. if i were too guess i would lean towards a controller issue. maybe the transmission control module or the pcm itself, i hate to say it but you should get it checked, they will usually quote you 1 hour for check out and wont go over that without talking to you, but throwing parts at it gets expensive very fast good luck:)

Sounds like the transmission went south. The torque converter goes bad in Chrysler vans.