Under pressure after the apparently never-ending story of the diesel exhaust gas scandal, the German minister of Transport and Digital Infrastructure, Alexander Dobrindt, ordered to pull some 22.000 Porsche Cayenne SUVs from VW subsidiary Porsche off the road. The government will impose a registration ban on the respective model until software updates are available that guarantee that first, the exhaust gas values for NOx are within the legal limits, and the exhaust gas cleaning mechanisms (which can negative affect the performance and fuel consumption of the car) are not bypassed in normal operation.
The defeat device in Porsche’s Cayenne recognizes if the vehicle is operated in a test stand. Then, the engine is put in a different driving mode with less NOx emission. This is much in line with similar software-controlled functions discovered in vehicles from other vendors like Fiat, but in the first place from Volkswagen and its subsidiary Audi. Actually, the 3.0 litre TDI V-6 diesel engines used in the Cayenne are supplied by Audi.