Diagnostic system for a lubrication circuit

A diagnostic system for a lubrication circuit of an internal combustion engine of a vehicle, the system comprising:

• a viscometer configured to detect a viscosity of a lubricating liquid of the lubrication circuit;
• a temperature sensor configured to detect a temperature of the lubricating liquid;
• an arrangement configured to determine a condition of use of the engine;
• a database which stores viscosity reference values for at least given temperatures of the lubricating liquid, given dates of last replacement of the lubricating liquid, and given conditions of use of the engine;
• and
• a control unit configured to acquire a state of the lubricating liquid based on the detected viscosity and a lubricating liquid condition of the lubricating liquid, the lubricating liquid condition including the temperature of the lubricating liquid, a date of last replacement of the lubricating liquid, and the condition of use of the engine, and configured to assess the state of the lubricating liquid by comparing the detected viscosity of the lubricating liquid with the viscosity reference values stored in the database as a function of lubricating liquid temperature, date of last replacement of the lubricating liquid, and use of the engine,
• wherein the control unit is configured to control, depending on the detected state of the lubricating liquid, actuation of a regeneration cycle of a filter of the lubrication circuit.