Method and device for controlling the functioning of a nitrogen oxide trap for an internal combustion engine running on a lean mixture

摘要

A method in which a first oxygen sensor is disposed on an exhaust pipe upstream from a nitrogen oxide trap, and development of a meaningful signal representative of the signal supplied by the sensor is monitored. A substantial increase of the meaningful signal, which is obtained following a variation resulting from a motor being switched from running on a lean mixture to running on a rich mixture, from a first plate having an essentially constant level is used as an indicator to control an end of a purge process. The method can be applied to diesel engines.