| 摘要 |
<p>The invention relates to a method, device and computer program product for diagnosing of a NOx-reducing catalyzer (4, 64, 94, 84a, 84b) that can be regenerated and/or of a three-way valve (69, 99, 89) for directing the flow of exhaust gases into a bypass pipe (70, 190, 87a, 87b) , and/or of a clean-up catalyzer (191, 91). All the components can be comprised in one and the same exhaust emission control system (82) . The diagnosing of the NOx-reducing catalyzer and of the three-way valve is carried out by method steps comprising measurement (pressure sensor 12, 612, 812, 812a, 812b) of the drop in pressure across the NO<SUB>x</SUB>-reducing catalyzer. The diagnosing of the clean-up catalyzer is carried out by method steps comprising measurement of the increase in temperature (temperature sensor 92, 192) in the clean-up catalyzer. In the event of reduced functionality of the NO<SUB>x</SUB> catalyzer, a deSO<SUB>x</SUB> is carried out. A fault code is generated in the event of reduced functionality of the three-way valve or of the clean-up catalyzer.</p> |
