transmission throwing several codes

I noticed the check transmission light is flashing and the vehicle starts off in second gear and does not go out of second gear while driving. it does have reverse so I took it to my dad's and put it on the scanner and it is throwing shift solenoid codes and torque converter codes. my dad says it sounds like it is electrical. I went and asked about transmission control module, but apparently there is none for that vehicle. I did notice that there is a plug. it is a three wire plug that is not plugged in somewhere coming off of a harness near the transmission. I was just wondering is there anything else that it could be before I go and try to replace the transmission? I am going to put up some images of the codes that it is throwing.