Ok heres the deal.
When I take off from a stop, if I hold the rpm's at a steady 1100 or so, the transmission will shift through all the gears.

I am literally doing 5 mph in overdrive. Then if I give it more gas it downshifts and takes off and shifts fine.

Does anyone know what might be causing this? Maybe the speed sensor?

 

That's what they do

 

No, it shifts through all the gears in about 3 seconds.
It never did this before but its all jerky and just not right

 

I'd unplugg the battery for like 30 minutes. it will reset the computer

 

Mine would do that when slowly headed uphill and completely load the motor in OD. Sounded like it was going to throw a rod the two times that it happened.

They reflashed mine and it hasn't happened since, although I haven't attempted to recreate the two situations where it happened either.