Abstract: System fault codes, component fault codes, and failure modes may be received at a system. A first level model comprising first level causal relationships and first level causal weights between the system fault codes and the component fault codes may be generated. A second level model comprising second level causal relationships and second level causal weights between the component fault codes and the failure modes may be generated. The first level model and the second level model may be combined to generate a model such as graphical model. One or more causal probabilities may be determined using the graphical model.

Abstract: A control system includes a jerk determination module and a misfire confirmation module. The jerk determination module determines a jerk of a crankshaft associated with a firing event in an engine. The misfire confirmation module selectively confirms that a misfire detected in the engine is valid based on the jerk.