Method for diagnosing an exhaust gas post-treatment

Abstract

Method for the on-board diagnosis of an exhaust gas post-treatment device for a combustion engine, wherein the exhaust gas post-treatment device has means for converting an exhaust gas component and wherein sensor means are provided downstream of the exhaust gas post-treatment device, wherein the exhaust gas component is acquired by the sensor means and that by means of the quantity of the acquired exhaust gas component the quality of the means for converting the exhaust gas component is derived, wherein a signal of the sensor means is transmitted to a system for the on-board diagnosis.

1 . A method for the on-board diagnosis of an exhaust gas post-treatment device for a combustion engine, comprising:
 providing an exhaust gas post-treatment device, a means of converting an exhaust gas component and a sensor means arranged downstream of the exhaust gas post-treatment device, wherein the exhaust gas post-treatment device has at least one carbon particle filter with a catalytic coating for converting the exhaust gas component;   acquiring the exhaust gas component by the sensor means and determining the quantity of the acquired exhaust gas component;   determining the quality of the means for converting the exhaust gas component;   transmitting a signal of the sensor means to a system for on-board diagnosis; and   regenerating the carbon particle filter, during which the exhaust gas component is produced.   
     
     
         2 . The method according to  claim 1 , wherein the exhaust gas component is acquired during a time interval, which extends from a first point in time during the starting phase of the regeneration at least up to a second point in time during the regeneration. 
     
     
         3 . The method according to  claim 2 , wherein the first point in time coincides with the start of the regeneration or a time after the start of the regeneration. 
     
     
         4 . The method according to  claim 1 , wherein the exhaust gas component is carbon monoxide, which content is determined by a carbon monoxide sensor. 
     
     
         5 . The method according to  claim 1 , wherein, when exceeding a threshold value of the quantity of the exhaust gas component, a signal of the sensor means is transmitted to the system for the on-board diagnosis. 
     
     
         6 . A device for on-board diagnosis of an exhaust gas post-treatment device for a combustion engine comprising an exhaust gas post-treatment device for converting an exhaust gas component and a sensor,
 wherein the exhaust gas post-treatment device has at least one carbon particle filter with a catalytic coating for converting the exhaust gas component,   the sensor means is arranged downstream of the exhaust gas post-treatment device, to detect an incomplete conversion of the exhaust gas component during a regeneration of the carbon particle filter by detecting the same, and   the sensor is connected to a system for the on-board diagnosis.   
     
     
         7 . The device according to  claim 6 , wherein the sensor means has a carbon monoxide sensor. 
     
     
         8 . The device according to  claim 6 , wherein the sensor for measuring the carbon monoxide is adapted from a lambda-sensor, a NOx-sensor or an electro-chemically operating sensor. 
     
     
         9 . The device according to  claim 6 , wherein the sensor has a catalytic coating and a temperature sensor.