Control method for thermal engine exhaust gases processing and vehicle using this method

The processing of exhaust gases of a heat engine is checked by checking the modeling of the trap by measuring a quantity of the nitrogen oxides stored in the trap by means of a sensor, comparing the measured quantity of nitrogen oxides to a modeled quantity of nitrogen oxides stored, and correcting the model if the measured quantity of nitrogen oxides is different from the modeled quantity by more than a further threshold. Checking the processing of exhaust gases (406) of a heat engine comprises checking the modeling of the trap (404) by measuring a quantity of the nitrogen oxides (NOx) stored in the trap by means of a sensor (408) located downstream of the trap, comparing the measured quantity of NOx to a modeled quantity of NOx stored, determined according to the model, and correcting the model if the measured quantity of NOx is different from the modeled quantity by more than a further threshold. NOx contained in the exhaust gases are stored and then reduced in a trap modeled such that the reduction of the NOx is actuated when the storage capacity of the trap, determined according to the model, reaches a threshold.