Feature models are widely used to represent product lines and they are key parts of the development process in agile methodologies such as generative and featureoriented programming. One of the most common problems in these cases is checking a feature model to be error-free. Some works cope with detecting errors in feature models, but automated explaination of errors is demanded in order to help the modeler to solve them. in this paper we propose a implementation-independent solution to explain the reasons why dead features, a common kind of error, appear in feature models, giving an implementation example.Ministerio de Ciencia y Tecnología TIC2003-02737-C02-0