Method and device for diagnosing an auxiliary heating function of an air mass sensor

A control unit for diagnosing a proper functioning of an auxiliary heater for preventing contamination of a sensor area in an air mass sensor in an engine system including an internal combustion engine, the air mass sensor being configured to communicate air mass information via a signal line and, if a specified state on the signal line is detected, to activate the auxiliary heater, the control unit comprising:

• an input stage configured to provide an input impedance and to set a specified state on the signal line;
• and
• a control unit logic configured to:
• (i) control the input stage in such a way that the state of the signal line is set to the specified state for a predefined time period in an auxiliary heater operating mode;
• (ii) receive a first temperature information before the activation of the auxiliary heater operating mode and a second temperature information after expiration of the predefined time period;
• and
• (iii) detect whether proper functioning of the auxiliary heater is present depending on the difference between the first temperature information and the second temperature information.

An engine system, comprising:

• an internal combustion engine;
• an air mass sensor;
• an auxiliary heater for preventing contamination of a sensor area in the air mass sensor;
• and
• a control unit;
• wherein the air mass sensor is configured to communicate air mass information via a signal line to the control unit and, if a specified state on the signal line is detected, to activate the auxiliary heater, and wherein the control unit includes:
• an input stage configured to provide an input impedance and to set a specified state on the signal line;
• and
• a control unit logic configured to:
• (i) control the input stage in such a way that the state of the signal line is set to the specified state for a predefined time period in an auxiliary heater operating mode;
• (ii) receive a first temperature information before the activation of the auxiliary heater operating mode and a second temperature information after expiration of the predefined time period;
• and
• (iii) detect whether proper functioning of the auxiliary heater is present depending on the difference between the first temperature information and the second temperature information.

A non-transitory, computer-readable data storage medium storing a computer program having program codes which, when executed on a computer, perform a method for diagnosing a proper functioning of an auxiliary heater in an air mass sensor in an engine system including an internal combustion engine, the auxiliary heater being used for preventing contamination of a sensor area, the air mass sensor being configured to communicate air mass information via a signal line during a sensor operating mode and, if a specified state on the signal line is detected, to activate the auxiliary heater, the method comprising:

• setting the state of the signal line to the specified state for a predefined time period in an auxiliary heater operating mode;
• gathering and transmitting by the air mass sensor (i) a first temperature information before the activation of the auxiliary heater operating mode and (ii) a second temperature information via the signal line after expiration of the predefined time period;
• and
• detecting whether proper functioning of the auxiliary heater is present depending on the difference between the first temperature information and the second temperature information.