Ecu has software in it that needs updated from time to time. Here at work we are going through all the 2014-2015 models because there was a large update put out last month.
In the future, please make a title that reflects what your problem is instead of a lazy one that 99% of the members will just scroll by and in the first post include all the information on your car (make, model, trim level, any mods, etc.). Can't help you if no one knows what it is you are working with.