SAFETY SYSTEM FOR CONTROLLING THE COMMUNICATION BETWEEN AT LEAST ONE CONTROL UNIT AND AN AUXILIARY DEVICE

A safety system (100) for controlling the communication between at least one control unit and an auxiliary device (1) in apparatuses for the on-board diagnostics of a vehicle (V) has been provided; the safety system comprises a communication line (15) for the data passage, a plurality of control units (C) in data communication with the communication line (15) and a device for interrupting the communication (12) configurable between an interruption condition and an enabling condition for selectively interrupting the communication between an auxiliary device (1) and the control units (C). The communication interrupting device (12) is active on the communication line (15) and separates a portion (15a) of the communication line (15) upstream the device (12) adapted to receive data from the auxiliary device and a portion (15b) of the communication line (15) downstream the device (12); the interruption condition interrupts the communication between the upstream portion (15a) and downstream portion (15b). A main driving unit (11) is programmed for configuring the communication interrupting device (12) in the interruption condition and/or enabling condition. The main driving unit (11) detects the data passing in the downstream portion (15b) of the communication line (15), determines a non-authorized access as a function of the condition of the interruption device and of the presence or not of data passing in the downstream portion (15b) of the communication line (15).