P0700 states the computer detected a transmission malfunction.
Unfortunatley, this is a rather vague code.
Many problems can cause this code to set.
The best way to diagnose this is thorugh data stream using a scantool and a few voltage checks.
Try swapping Electronic Automatic Transaxle (EATX) relay with another relay. Check fuse #17 in PDC
Check both the transmission input and output shaft speed reading on scantool.
Check that the solenoids are working correctly and that the tcc solenoid locks and unlocks correctly using data stream. Ohm test the solenoids at the transmission connector.
Remove the pan, check for contaminants and condition of filter.
If all looks good, a transmission overhaul.
Most common problems are speed sensors and faulty solenoids. It is suggested that if a faulty speed sensor is found you replace the sensors in pairs. The solenoids are serviced as the solenoid pack and can not ba replaced individually.
I apoligize that your knowledge of transmissions is limited. There is nothing wrong with that. But, that does not change the problem at hand.
However, today's transmissions are very complex units being controlled by complex computers. So, this becomes a complex problem with a complex answer.
I'm very dissapointed that you will not accept my answer. Especially considering the information you were just given.
I'll try to put it into simpler terms.
You could have a faulty speed sensor. If this is the case you can replace the 2 speed sensors and be set.
You can have a faulty solenoid. In this case, the valve body needs to be removed and then the solenoids can be relpaced.
You can have an internal transmission fault which would require a transmission overhaul.
You can have a clogged transmission filter.
Since todays transmissions are computer controlled... Diagnosing this problem requires the use of a scantool ( a compute capable of communicating with the transmission computer).