Got P1747 and OD light flashing.. PLEASE HELP

[street_legal?]

I have a p1747 Electronic Pressure Control Solenoid is faulty of sticking..
Its OK when its cold for about 1 mile and it sticks of quits.. It make the trans OD light flash and it shifts all weird.. No overdrive lockup and the whole bit.. I have a TC lock up switch so i can still drive it but the trans is not happy with this code... What is involved with the pressure solenoid? do i have to replace the whole valve body or just the switch?
Ive already check the wiring and what not.

Is this a good time to upgrade the valve body?
or is it just drop the pan, plug and play deal?

ANY AND ALL HELP IS GREAT!