METHOD AND DEVICE FOR OPERATING EXHAUST GAS SENSORS

摘要

The invention relates to a method and a device, in particular a control and evaluation unit, for operating at least one exhaust gas sensor for monitoring the functionality of an emission control system in the exhaust tract of an internal combustion engine, wherein the exhaust gas sensor is operated at least intermittently at high temperatures and has a thermal shock sensitivity inherent to the design, and in which a heating phase can be implemented at least intermittently prior to a regeneration phase or prior to a measuring operation phase, wherein a clearly lower temperature is set in this heating phase in comparison to the regeneration temperature or the measuring operation temperature. According to the invention, the function for dew point recognition and re-release of a dew point end is adaptively implemented and influenced by at least one water detection criterion or at least one flood detection criterion. By this means, an improved dew point detection is achieved after driving through water, as a result of a significant reduction of tolerances and an earlier release of the dew point end for the exhaust gas sensor.

主权项

1. A method for operating at least one exhaust-gas sensor for monitoring functionality of an exhaust emission control system in an exhaust train of an internal-combustion engine (10), wherein the exhaust-gas sensor is operated at high temperatures at least temporarily and, due to its type of construction, exhibits a sensitivity to thermal shock, and in which prior to a regeneration phase or prior to a measuring-mode phase a heating phase can be carried out at least temporarily, wherein in this heating phase a distinctly lower temperature is adjusted in comparison with the regeneration temperature or measuring-mode phase, characterized in that a dew-point detection and re-enabling of a dew-point end are carried out adaptively and are influenced by at least one fording-detection criterion or at least one flood-detection criterion.