A system for detecting and locating failures in a complex system, comprising: - at least one sensor for delivering a signal (S CAP) representing the functioning of a component (COMP) of the said complex system; - at least one module (MOD VAL) validating the proper functioning of the said at least one sensor capable of analysing the said signal (S CAP) and of delivering: - at least one validated signal (SIG VAL) associated with a so-called « first order » confidence level; or - a message (MSG CAP) representing a failure of the said at least one sensor; - a failure detection module (MOD DP) capable of detecting a failure affecting at least one sub-system (SS1, SS2) or a component (COMP) from the said validated signal (SIG VAL) and, if such a failure is detected, of generating at least one raw failure message (MSG PB) comprising raw information (INF PB) on the said failure and a so-called « second order» confidence level; - a data merging module (MOD FD) which, at least from a said raw failure message (MSG PB) or from said message (MSG CAP) representing a failure of at least one sensor, is capable of generating a consolidated failure message (MSG PC) comprising consolidated information (INF PC) on a failure affecting at least one sub-system (SS1, SS2) of the said complex system or a component and a so-called «third order » confidence level; and - a decision-making module (MOD PD) capable of obtaining the said consolidated failure message (MSG PC) and of deciding, using a fuzzy logic technique at least one corrective action in relation to the diagnosed failure that is to be taken in relation to: - the said consolidated information on a failure (INF PC); - the said third order confidence level; and - a level of seriousness of the said failure obtained from a knowledge database, the corrective action to be taken consisting of stopping the complex system, of deactivating, activating or reactivating a component of said complex system, of modifying its point of functioning or of sending a request to a regulating system. - at least one sensor for delivering a signal (S CAP) representing the functioning of a component (COMP) of the said complex system; - at least one module (MOD VAL) validating the proper functioning of the said at least one sensor capable of analysing the said signal (S CAP) and of delivering: - at least one validated signal (SIG VAL) associated with a so-called « first order » confidence level; or - a message (MSG CAP) representing a failure of the said at least one sensor; - at least one validated signal (SIG VAL) associated with a so-called « first order » confidence level; or - a message (MSG CAP) representing a failure of the said at least one sensor; - a failure detection module (MOD DP) capable of detecting a failure affecting at least one sub-system (SS1, SS2) or a component (COMP) from the said validated signal (SIG VAL) and, if such a failure is detected, of generating at least one raw failure message (MSG PB) comprising raw information (INF PB) on the said failure and a so-called « second order» confidence level; - a data merging module (MOD FD) which, at least from a said raw failure message (MSG PB) or from said message (MSG CAP) representing a failure of at least one sensor, is capable of generating a consolidated failure message (MSG PC) comprising consolidated information (INF PC) on a failure affecting at least one sub-system (SS1, SS2) of the said complex system or a component and a so-called «third order » confidence level; and - a decision-making module (MOD PD) capable of obtaining the said consolidated failure message (MSG PC) and of deciding, using a fuzzy logic technique at least one corrective action in relation to the diagnosed failure that is to be taken in relation to: - the said consolidated information on a failure (INF PC); - the said third order confidence level; and - a level of seriousness of the said failure obtained from a knowledge database, the corrective action to be taken consisting of stopping the complex system, of deactivating, activating or reactivating a component of said complex system, of modifying its point of functioning or of sending a request to a regulating system. - the said consolidated information on a failure (INF PC); - the said third order confidence level; and - a level of seriousness of the said failure obtained from a knowledge database,