Electric power steering assist not working

My car's electric power steering assist began to stop working while driving to school ( it was working perfectly fine). I pulled over and restarted the car and the car alternated between working and not working. It eventually stopped working completely. Now I have a stability trak and steering assist reduce message on my dashboard. I am, unfortunately, out of warranty. I did some research on older models, as I was not able to find any information on the current gen Malibu. I decided to purchase a motor of from eBay and replace it with the one in my car before going to the dealer, as they charge just $140.00 to diagnose the car. Unfortunately, after replacing the motor, the problem remains. I've read that some people have had to have the motor/sensor reprogrammed in the previous gen of Malibu's. My question is, if I should return the motor I purchased ($90.00) and take the vehicle to the dealer? Or do you know if current gen Malibu's need to have the steering motor reprogrammed? I know the best thing to do is to take the vehicle to the dealer, but I'm someone who likes to learn about the mechanics of a vehicle.