'98 Dakota tranny problem

this weekend was driving the truck and after coming to a full stop, I pushed the accelerator down and the engine rev'ed up to about 2-3000 rpm but the truck was not moving. Check engine light came on. I shut the truck off for about 15 minutes and when I turned it on it seemed to work fine after that. While driving home I did have one instance where it did not want to shift out of 1st. Put the scan tool on when I got home and both engine and transmission codes read P0720 Output Speed Sensor Malfunction. Does this scenario sound typical of this type of malfunction? My first thought was that 1st went out on my tranny. Its the automatic transmission btw. Checked the fluid level and quality and level was fine and was not burnt.