Method and device for diagnosing a leakage of a crankcase ventilation line of a crankcase ventilation device for an internal combustion engine

A device for leakage diagnosis of a crankcase ventilation line of a crankcase ventilation device for an internal combustion engine, the device comprises:

• a control unit configured to control a method, the method comprising:
• influencing the introduction of gas along a crankcase aeration line into a crankcase of the internal combustion engine;
• acquiring a measurement signal profile by an exhaust-gas sensor arranged in an exhaust-gas tract of the internal combustion engine, the measurement signal profile is characteristic of at least one exhaust-gas property of the exhaust gas in the exhaust-gas tract, the exhaust-gas property influenced by the influencing of the introduction of gas into the crankcase;
• providing an expected measurement signal profile characteristic of the exhaust-gas property of the exhaust gas in the exhaust-gas tract based on the influence of the introduction of gas into the crankcase;
• comparing the acquired measurement signal profile with the expected measurement signal profile;
• and
• identifying a leak in the crankcase ventilation line when, based on the comparison, the acquired measurement signal profile deviates from the expected measurement signal profile by at least a predetermined threshold value, the crankcase ventilation line discharging gases from the crankcase into the intake tract of the internal combustion engine,
• wherein the internal combustion engine has a tank ventilation device which is fluidically connected to the crankcase aeration line by a tank ventilation valve, wherein gases are introduced from the tank ventilation device by the tank ventilation valve for the influencing of the introduction of gas into the crankcase, or
• wherein the internal combustion engine has an exhaust-gas recirculation device which is fluidically connected to the crankcase aeration line by an exhaust-gas recirculation valve, wherein gases are introduced from the exhaust-gas recirculation device into the crankcase by the exhaust-gas recirculation valve for the influencing of the introduction of gas into the crankcase.