Method for detecting a voltage offset at least in a portion of a voltage lambda characteristic curve

A non-transitory computer-readable medium on which are stored instructions that are executable by a processor and that, when executed by the processor, causes the processor to perform a method for a two-point lambda sensor that is situated in an exhaust duct of an internal combustion engine and that is used for a regulation setting an air/fuel mixture supplied to the internal combustion engine, the method comprising:

• in a first regulation:
• with reference to voltage and lambda value pairs of a reference voltage-lambda characteristic curve of the two-point lambda sensor, which value pairs each includes a respective voltage value of the sensor and a respective lambda value, changing a composition of the air/fuel mixture supplied to the internal combustion engine from a predefined lambda value to lambda=1;
• and
• determining a first delay time of the voltage value reaching a value corresponding to the lambda=1 in response to the changing performed in the first regulation;
• in a second regulation:
• with reference to the voltage and lambda value pairs of the reference voltage-lambda characteristic curve, changing the composition of the air/fuel mixture supplied to the internal combustion engine from the predefined lambda value to lambda=1;
• determining a characteristic of the changing of the composition performed in the second regulation based on the first delay time determined for the first regulation;
• determining an actual value of lambda on an actual voltage-lambda characteristic curve of two-point lambda sensor that corresponds to the predefined lambda value of the reference voltage-lambda characteristic curve based on the determined characteristic;
• and
• identifying a voltage offset of the actual voltage-lambda characteristic curve from the reference voltage-lambda characteristic curve based on a deviation of the actual value of lambda from the predefined lambda value;
• wherein the first and second regulations are carried out responsive to a determination that a threshold value of a property of an injected quantity of fuel supplied to the internal combustion engine is reached.

An electronic control device comprising a processor, wherein the processor is configured to perform a method for a two-point lambda sensor that is situated in an exhaust duct of an internal combustion engine and that is used for a regulation setting an air/fuel mixture supplied to the internal combustion engine, the method comprising:

• in a first regulation:
• with reference to voltage and lambda value pairs of a reference voltage-lambda characteristic curve of the two-point lambda sensor, which value pairs each includes a respective voltage value of the sensor and a respective lambda value, changing a composition of the air/fuel mixture supplied to the internal combustion engine from a predefined lambda value to lambda=1;
• and
• determining a first delay time of the voltage value reaching a value corresponding to the lambda=1 in response to the changing performed in the first regulation;
• in a second regulation:
• with reference to the voltage and lambda value pairs of the reference voltage-lambda characteristic curve, changing the composition of the air/fuel mixture supplied to the internal combustion engine from the predefined lambda value to lambda=1;
• determining a characteristic of the changing of the composition performed in the second regulation based on the first delay time determined for the first regulation;
• determining an actual value of lambda on an actual voltage-lambda characteristic curve of two-point lambda sensor that corresponds to the predefined lambda value of the reference voltage-lambda characteristic curve based on the determined characteristic;
• and
• identifying a voltage offset of the actual voltage-lambda characteristic curve from the reference voltage-lambda characteristic curve based on a deviation of the actual value of lambda from the predefined lambda value;
• wherein the first and second regulations are carried out responsive to a determination that a threshold value of a property of an injected quantity of fuel supplied to the internal combustion engine is reached.