State e.g. operating state, diagnosing method for particle filter in heat engine of motor vehicle, involves determining rate of change of parameter relative to variable, and comparing rate of change of parameter to predetermined threshold

摘要

The method involves calculating a parameter, and determining a rate of change of the parameter relative to a variable, where the variable is constituted by a soot quantity contained in a particle filter (2) of an exhaust system (3). The rate of change of the parameter is compared to a predetermined threshold to determine a state of the particle filter. The calculation of the parameter is carried out by calculating a ratio of maximum temperature in the particle filter on temperature of gas at an inlet of the particle filter. An independent claim is also included for a device for diagnosing a state of a particle filter of an exhaust system of a heat engine.