| CPC F02D 41/1495 (2013.01) [F02D 41/1401 (2013.01); F02D 41/1494 (2013.01); F02D 41/222 (2013.01); F02D 2041/1433 (2013.01); F02D 41/1454 (2013.01)] | 10 Claims |
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10. An electronic control unit configured to diagnose a heating element of an exhaust gas sensor of an engine systme that includes an internal combustion engine, the electronic control unit configured to perform a method, the method including the following steps:
while a temperature at the exhaust gas sensor is at a start temperature value, operating the heating element to initiate a heating process that increases the temperature of the exhaust gas sensor in order to attain an enable condition; and
based on reaching the enable condition due to the heating process:
identifying a current actual temperature value of the temperature at the exhaust gas sensor using a temperature sensor and identifying a modeled expected temperature value of the temperature at the exhaust gas sensor based on a present state of the engine system that is dependent on operating conditions of the engine system, wherein the present state is determined based on one or more sensor output;
ascertaining a temperature difference between the modeled expected temperature value of the temperature at the exhaust gas sensor and the identified current actual temperature value of the temperature at the exhaust gas sensor; and
diagnosing the heating element of the exhaust gas sensor as defective when the ascertained temperature difference exceeds a predefinable temperature threshold value;
wherein the method includes at least one of the following four features (I)-(IV):
(I) the method further comprises identifying the start temperature value with a start of the heating process, the enable condition being attained upon exceedance of the start temperature value by a predefinable temperature increase;
(II) the method further comprises ascertaining a heat quantity introduced by the heating process, the ascertainment being performed as a function of a model according to which the modeled expected temperature value is identified, the enable condition being determined to be reached when the ascertained heat quantity exceeds a predefinable heat quantity;
(III) a setpoint temperature value for the heating process is predefined, the enable condition being determined to be reached at a point in time when the modeled expected temperature value reaches or exceeds the predefined setpoint temperature value, an actual value of the temperature coinciding with the point in time being selected as the current actual temperature value based on the enable condition being reached; and
(IV) the modeled expected temperature value is ascertained as a function of a temperature of an intake air of the internal combustion engine, of a battery voltage of the internal combustion engine, of a pulse width-modulated activation ratio for the heating element of the exhaust gas sensor, of a wall temperature at the point of the exhaust gas sensor, of an exhaust gas temperature, and of a coolant temperature at the output of an internal combustion engine.
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