I fixed my -9 reading on freezer side. It turned out to be a bad thermistor wire (not the actual thermistor on the wire). I ran a diagnostic and it told me what thermistor connection wasn't reading. Now I am not going to tear the back out of my fridge and find the wires and rethread it through the fridge.
So I did the quickest and most efficient method. I ran a new wire connected to the mother pins outside over the top of the fridge and Into the freezer. The wire is so thin it doesn't cause a problem when the freezer door closes. It's been working well for over two years now. The thermistor is just to taped to the inside wall of the freezer. Hey it works.