Another Caravan transmission question

Hi,
I have a 99 Dodge Caravan sport. It has 177,000 miles (most are highway). A few nights ago I came into town and stopped at a red light. As I started forward my speedometer went to zero and (stopped functioning) and the van seems to be stuck in 1st gear. It drives fine, but wont' come out of first. I checked the computer codes and found the following:

700 - Transcontrol system malfunction
(listed twice)
500 - vehicle speed sensor A malfunction
(listed twice)
731 - Gear #1 Ratio incorrect
720 - output speed sensor

Do I need a new transmission?

thanks

jb