A method for diagnosis of functional faults in a functional architecture, including a unit of functions connected to electronic components, producing and using data, at least one datum of which can adopt a fixed pre-determined value, following occurrence of an erroneous functioning of at least one of the components of the unit. The method, while having a unit of functions and carrying out a function for which the input and output data can be assigned to sensors or actuators, determines particular values during which the particular values corresponding to functional faults for the sensors and actuators are listed and generates the functional diagnostic for the function as a function of the lists determined during the determining.