01 Voyager V6 (Flex Fuel Model)
 

My van stopped shifting last night and the trans light came on. We hooked it up to our code reader and two codes came up...P0605 Internal Control Module and P0700 Transmission Control System. Anyone know how to fix this? Is it just a new sensor, or computer update?

You need a new Tranmission Control Module. The p0700 is a code in the PCM telling scanner that a code is present in the TCM. P0605 Internal TCM is the TCM code.

No repair just replace. Don't be surprised if there is a code in the new one after it's done. Sometimes there is, sometimes there is not.