Method and device for monitoring a heating device of a sensor mounted in the exhaust system of an internal combustion engine

A method for monitoring a heating device of a sensor mounted in an exhaust system of an internal combustion engine, comprising the steps of:

• forming a first signal indicative of an operational readiness of the sensor;
• forming a second signal indicative of a temperature of the sensor;
• and
• determining an operational state of the heating device as a function of the first signal and the second signal, the operational state including one of a working order and a non-working order, and a no-statement order, the heating device being in the working order when the first signal indicates the operational readiness of the sensor and the second signal has a value within a predetermined first range, the no-statement order existing when the first signal indicates the operational readiness of the sensor and the second signal is within a predetermined third range.

A method for monitoring a heating device of a sensor mounted in an exhaust system of an internal combustion engine, comprising the steps of:

• forming a first signal indicative of an operational readiness of the sensor;
• forming a second signal indicative of a temperature of the sensor;
• determining an operational state of the heating device as a function of the first signal and the second signal, the operational state including one of a working order and a non-working order, the heating device being in the working order when the first signal indicates the operational readiness of the sensor and the second signal has a value within a predetermined first range;
• and
• forming a fundamental signal as a function of an air flow rate signal through the internal combustion engine,
• wherein the step of forming the second signal includes forming the second signal as a function of the fundamental signal and at least one correction signal.

A device for monitoring a heating device of a sensor mounted in an exhaust system of an internal combustion engine, comprising a control unit coupled to the sensor, the control unit

• forming a first signal indicative of an operational readiness of the sensor,
• forming a second signal indicative of a temperature of the sensor,
• determining an operational state of the heating device as a function of the first signal and the second signal, the operational state including one of a working order and a non-working order, the heating device being in the working order when the first signal indicates the operational readiness of the sensor and the second signal is within a predetermined first range, and
• forming a fundamental signal as a function of an air flow rate signal through the internal combustion engine,
• wherein the second signal is formed as a function of the fundamental signal and at least one correction signal.