Abstract: The system enables the diagnosis of anomalies or breakdowns in a plurality of types of electronic control systems (S), each of which includes, in known manner, a plurality of sensors (2) and electrically-controlled actuators (3) connected to an electronic control and operating unit (1), which is different for each type of control system (S). This unit (1) is programmed to carry out auto-diagnosis of anomalies or breakdowns in the control system (S) and to provide serial-type electrical auto-diagnosis signals at an output (5), the signals containing information on the operating conditions of the control system (S). The various control systems (S) each have the same standard electrical connector (6) connected to the output (5) of the respective control unit (1). Each time it is actuated, the electronic control unit (1) of each system (S) outputs at the output (5) a serial-coded identification message of the type of control system (S) to which the unit (1) belongs.