Zykluserkennung, Thermofenster & Co: Die Tricks der Autohersteller

The tricks of the car manufacturers.

Car manufacturers will use almost any means to manipulate the emissions of their diesel vehicles - and the authorities have so far let them do so. Here you will find an overview of the most common methods.

Car manufacturers are doing a lot to reduce fuel consumption and keep emissions within legal limits. This includes the use of innovative, weight-saving materials for lighter bodies and components, efficient coordination and optimization of engine control, and various technologies for exhaust gas purification. For diesel vehicles, which emit harmful nitrogen oxides (NOx) in addition to CO2, car manufacturers are using methods such as AdBlue injections, SCR catalysts, exhaust gas recirculation or NOx storage catalysts.

These technologies are effective, but they have one disadvantage: they reduce engine performance, cause engines to wear out more quickly and cause higher costs and increased maintenance. High engine performance and environmental compatibility can only be achieved with increased effort. Effective catalytic converters make vehicles clean, but they are also expensive and reduce sales opportunities.

Software manipulation instead of effective exhaust gas purification

Software solutions that deactivate exhaust gas purification or recirculation under certain operating conditions are cheaper for manufacturers. The result: On the test bench, diesels are clean, but on the road they mutate into polluters whose emissions often exceed the limit values many times over. According to Regulation EC 715/2007, Article 5, Paragraph 1, defeat devices that reduce the effectiveness of the emission control system are prohibited. However, Article 5, Paragraph 2 provides for exceptions: for example, to protect the engine from damage (for example in cold outside temperatures), when starting and under special defined conditions in test procedures.

Car manufacturers make exceptions to the rule

The car manufacturers interpret these exemptions extremely extensively and justify illegal shutdown devices such as cycle detection or thermal windows with the protection of the engine. The responsible authorities still approve of this practice today. Although the manufacturers have been obliged to provide software updates, these do not make the vehicles cleaner in real operation. In some cases, nitrogen emissions even increase further, as a report by the ZDF magazine "Frontal 21" shows.
The flimsy argument of engine protection is likely to be over soon. The Advocate General of the European Court of Justice (ECJ) has declared defeat devices inadmissible - as have many regional and higher regional courts. In her opinion of April 30, 2020 (case number C-693/18), she comes to the conclusion that "only immediate risks of damage that impair the reliability of the engine and pose a concrete danger when driving the vehicle can justify the presence of a defeat device." In any case, the aim of delaying wear or contamination of the engine does not justify the use of a switch-off device.