Integrated architectures promise substantial technical and economic benefits in the development of distributed embedded real-time systems. In the context of diagnosis new diagnostic strategies can be applied by taking the physical and functional structure of an integrated system into account. In this paper we present a diagnostic framework that is designed to tackle prevalent diagnostic problems industry is currently facing, such as the trouble-not-identified phenomenon in electronic systems. So-called Out-of-Norm Assertions (ONAs) are employed that combine diagnostic information to correlate experienced failures in order to decide on the type fault (e.g., transient vs. permanent, internal vs. external) affecting the system. Based on a prototype implementation of the integrated time-triggered DECOS architecture we show the feasibility of this diagnostic strategy.