How can I fix the wrench signs that shows up on my Ford edge 2012?

I have a Ford Edge Limited 2012 model. I was driving when the wrench warning light came on then the car began to decelerate even as I was pressing the accelerator, and going through the manual the wrench sign is a Powertrain malfunction/reduced power (RTT). After waiting a few seconds later the car would start and run as normal. What do I need to do to get it running back to normal?