Had a bit of an issue when I got mine - no overdrive at all!
P0700 on the dash just means that transmission ECU is throwing out a code.
I had an OBD2 scanner and it was telling me 'incorrect gear ratio in 1st'
Usually means one or both of the sensors on the gearbox are shot. Replaced mine (its a cheap part - $36 from memory (each)) and can be done without jacking the car up.
Gearbox was smooth as silk just replacing those two - about an hour for the pair.
Rather specific troubleshooting thread for the error I was getting here