Use of on-board diagnosis apparatus for monitoring nitrogen oxide absorption catalyst regeneration, includes examination of reliability-critical components on detection of anomalies

摘要

Catalyst loading with nitrogen oxides (NOx) is determined, and compared with a maximum limit. An on-board diagnosis apparatus monitors catalyst activity. On exceeding the limit or detecting irregularity in catalyst activity, in a third stage, reliability of NOx regeneration is examined. Correct function of components relevant to reliability is examined, and/or current operation is examined through observation of predetermined parameters. It is examined whether, meeting predetermined regeneration parameters, an NOx regeneration can be undertaken, if necessary adjusting the required NOx regeneration parameters, and introducing the NOx regeneration given permissibility of such a measure, otherwise repeating the third stage and/or if appropriate signaling a detected functional disturbance of a component relevant to reliability. NOx regeneration is carried out until a predetermined NOx regeneration level is achieved. Normal operational conditions are set and reversion to the start, or premature discontinuation or interruption of the NOx regeneration, in the case that the actual results of the reliability examination of the third stage, if necessary returning to the start or the third stage, and/or if appropriate signaling detection of a functional defect of one of the components relevant to reliability.