Transmission not shifting from low gear

Code 700 just means there is a fault code in the Transmission Computer. Most simple code readers only read codes in the Engine Computer. You'll likely need to find a mechanic with a scanner that can access the Transmission Computer to read those codes.

Be aware fault codes never say to replace a part or that one is bad. They only indicate the circuit or system that needs further diagnosis. When a sensor or other part is referenced in a fault code, it is actually the cause of that code about half of the time. First we need to rule out wiring and connector terminal problems, and mechanical problems that are detected by the computer.

I can interpret the codes for you once you post them in your reply.