Diagnostics for recognition of fault models in a common ramp diesel injector commands, in which one or more fault symptoms are linked to a physical fault

Diagnostic method using recognition of a fault model, which links one or more fault symptoms (9) with a physical fault (7). The fault symptoms (9) are associated with a fault model (19). The fault models (19) are combined in a logical way to model matrix (16) and a selection matrix (15) which contain data concerning the known physical faults (7). Bits of the fault model are important for detection of a particular physical fault. Diagnostic by XOR combination of the fault model (19) bit by bit with a recording of the model matrix (16). The result of the XOR combination is combined bit by bit with each recording of the selection matrix (15) according to an AND combination having the same index as the recording of the model matrix combined by the XOR combination with the fault model (19). In the case of successful model recognition, a particular physical fault (7) is recognized. Non recognition is an unclassable fault (14). The recognition result is sent to a fault memory (18). Procédé de diagnostic par reconnaissance de modèles de défaut associant un ou plusieurs symptômes de défaut (9) à un défaut physique (7). Les symptômes de défaut (9) sont appliqués à un modèle de défaut (19) qui combine ce symptôme à une ou plusieurs matrices (15, 16); les informations de matrice contiennent des défauts physiques (7), connus par le modèle de défaut (19). La présente invention s'applique tout particulièrement au diagnostic de situation de défaut dans des commandes d'injecteur (8) d'un système d'injection à rampe commune Diesel.