Difference between the various defeat devices diesel scandal
In the course of the diesel scandal, no word has been used as often as the word "defeat device". Even though it has become part of common usage at the latest since the VW diesel scandal, there are still some ambiguities.
What exactly is a defeat device?
How do the devices of individual manufacturers differ?
And how are these to be legally evaluated?
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Shahroch Taleqani
Definition of defeat devices in the diesel scandal
A defeat device within the meaning of Art. 3 no. 10 of Regulation (EC) 715/2007 means a "component of a design which senses temperature, vehicle speed, engine speed, gear ratio, intake manifold vacuum or other parameters in order to activate, deactivate, delay or modify the operation of any part of the emission control system so as to reduce the effectiveness of the emission control system under conditions which may reasonably be expected to be encountered in normal vehicle operation" (LG Dessau, judgment of 14.04.2022).
So, simply put, the RV Fiat diesel scandal is about a device that shuts off, alters, or shuts down certain functions, causing the engine's emission levels to worsen.
The questionable vehicles in the emissions scandal have one thing in common, regardless of which manufacturer they come from: they all have some kind of defeat device installed. However, these are not identical. The three most prominent examples are probably the VW engine's changeover logic, the thermal window, which is mainly blamed on Mercedes, and the so-called timer.
Test bench detection
The first company to fall out of favor with the general public in connection with the emissions scandal was VW. The highest court has already ruled that the defeat device installed in the VW-EA 189 engines is illegal.
The defeat device installed in these VW engines in connection with the diesel scandal recognized the test situation on the basis of certain parameters and in such cases switched to a mode in which more exhaust gases are returned to the engine, which reduces nitrogen oxide emissions. Conversely, the software switches to a different mode outside the test bench. In this mode, exhaust gas recirculation is reduced and consequently NOx emissions increase.
In this respect, the software recognizes the vehicle's operating mode on the basis of technical parameters. In other words, whether it is in a test cycle or in actual driving mode. Accordingly, the exhaust gas recirculation is activated or deactivated, which impairs the effectiveness of the emission control system (see BGH ruling dated January 8, 2019 - VIII ZR 225/17).
Thermal window
Mercedes probably uses a so-called thermal window in some engines affected by the emissions scandal. With the thermal window, the outside temperature is determined and exhaust gas recirculation is modified in such a way that it functions optimally within a certain temperature range (20°C to 30°C), while below this range (20°C to 5°C) it is gradually reduced to almost zero.
Timer
In contrast, Fiat is said to have developed a time-coupled defeat device in the diesel scandal. The so-called timer causes the exhaust gas recirculation rate to be greatly reduced or deactivated after about 22 minutes, or after a set number of regeneration cycles. This causes the engine to be clean during the NEDC test cycle, which also lasts about 22 minutes, but not beyond. This is because once the 22 minutes have elapsed, and thus also at the end of the test bench, exhaust gas recirculation is reduced and emission levels rise very sharply.
Legal assessment
The differences in the way the defeat devices work also means that they have to be assessed differently in legal terms in the Fiat diesel scandal.
The ECJ recently ruled on whether the thermo window is to be considered an inadmissible defeat device in the context of the emissions scandal with regard to VW and Porsche. However, the legal assessments can also be applied to thermowindows in other vehicles, as the question of inadmissibility concerns the functioning of the thermowindow in general. Here, the ECJ ruled "that a device which ensures compliance with the limit values provided for in (...) [Regulation No. 715/2007] only when the outside temperature is between 15 and 33°C (...) constitutes a defeat device within the meaning of (...) [that Regulation]" (ECJ C-134/20) and is thus in principle impermissible. In uncomplicated terms, the ECJ has now ruled for the diesel scandal that a defeat device which throttles the exhaust gas purification depending on the outside temperature is to be assessed as illegal.
In the case of the defeat device used by VW, it has already been clarified by the highest courts that such a switching logic constitutes an impermissible defeat device. The Federal Court of Justice (BGH) has ruled that such a device, which ensures that the exhaust emission values are only complied with on the test bench, constitutes an impermissible defeat device within the meaning of Article 5 (2) sentence 1 of Regulation (EC) No. 715/2007 (see BGH ruling dated January 8, 2019 - VIII ZR 225/17).
It has not yet been fully determined how the timer is to be legally assessed. Some assume that this is also an impermissible defeat device.
Conclusion
One thing is therefore clear; the defeat devices used in connection with the diesel scandal are relatively indisputably to be classified as impermissible defeat devices. However, this does not mean that every consumer who has purchased a vehicle with such a device is also entitled to compensation.
The problem is now, and was already in the proceedings against VW, mainly to prove that the respective groups have acted intentionally and immorally. These are two of the requirements of Section 826 of the German Civil Code (BGB), which has been used by German courts as the relevant basis for claims in most cases to date.
However, this could now change soon, a further case law of the ECJ is expected also with relevance for the Fiat diesel scandal, in which the request of the Advocate General is directed to decide that Regulation (EC) No. 715/2007 constitutes a protective norm within the meaning of Section 823 (2) of the German Civil Code. This could have a major impact on the proceedings in the Fiat diesel scandal.
This is because Section 823 (2) of the German Civil Code (BGB) allows negligence to suffice as a prerequisite. This would eliminate the difficult problem of proving intentional, immoral damage. It now remains to be seen whether the ECJ will rule in favor of the Advocate General's application or not.
