Method and device for managing the operation of a nitrogen oxide trap, and diagnosing its ageing condition

A device that manages an operation of a nitrogen oxide trap and that diagnoses an aging condition of the nitrogen oxide trap for an internal combustion engine, comprising:

• a first oxygen probe placed on an exhaust line downstream of the nitrogen oxide trap;
• temperature means for determining whether the first oxygen probe operates at a high temperature or a low temperature;
• and
• computation means for determining a unique substantial increase of a significant signal representative of a signal delivered by said probe from a start of bleeding the nitrogen oxide trap, the unique substantial increase of said significant signal toward a threshold value S1 being an indicator of an end of the bleeding, and for determining the aging condition of the nitrogen oxide trap, wherein
• when the temperature means determines that the first oxygen probe operates at the low temperature, the computation means integrates the significant signal over a time from the start of the bleeding to the end of the bleeding to determine an integration value and compares the integration value with a threshold value S2 to diagnose the aging condition of the nitrogen oxide trap, and
• when the temperature means determines that the first oxygen probe operates at the high temperature, the computation means measures the time elapsed to reach the threshold S1 from the start of the bleeding to diagnose the aging condition of the nitrogen oxide trap.

A device that manages an operation of a nitrogen oxide trap and that diagnoses an aging condition of the nitrogen oxide trap for an internal combustion engine, comprising:

• a first oxygen probe placed on an exhaust line downstream of the nitrogen oxide trap;
• a computation unit configured to determine whether the first oxygen probe operates at a high temperature or a low temperature, and configured to determine a unique substantial increase of a significant signal representative of a signal delivered by said probe from a start of bleeding the nitrogen oxide trap, the unique substantial increase of said significant signal toward a threshold value S1 being an indicator of an end of the bleeding and for determining the aging condition of the nitrogen oxide trap, wherein
• when the computation unit determines that the first oxygen probe operates at the low temperature, the computation unit integrates the significant signal over a time from the start of the bleeding to the end of the bleeding to determine an integration value and compares the integration value with a threshold value S2 to diagnose the aging condition of the nitrogen oxide trap, and
• when the computation unit determines that the first oxygen probe operates at the high temperature, the computation unit measures the time elapsed to reach the threshold S1 from the start of the bleeding to diagnose the aging condition of the nitrogen oxide trap.