Frigidaire side by side frost free freezer coils are freezing up and then refrigerator gets too warm. Replaced the controller in the freezer compartment but still doing the same thing.

It sounds like your defrost system is down. It has a timer, a heater, and a defrost thermostat. You can just replace all three parts and be done with it since they all three burn out at the same time. Defrost the freezer to get at the heater and defrost thermostat and the timer can be at the bottom of the refrigerator or next to the thermostat and has a one-way screw on the front made of plastic. You can look at the defrost heater and see if it is bad. It will be burned in two. The timer you can test by turning it to see if it first turns everything off and then after 20 minutes it does not come back on.