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"Temperature Windows are Prohibited Defeat Devices" - European Court of Justice

9th January 2023


GSMB Invest GmbH & Co. KG -v- Auto Krainer Gesmbh C-128/20

14 July 2022

The European Union has regulations for type approval of light passenger and commercial vehicles with respect to their emissions. The relevant regulation (715/2007) prohibits in vehicles the installation of devices which sole utility is to reduce the effectiveness of emission control systems in light passenger and commercial vehicles for their type approval. Article 3(10) of the Regulation classifies such devices as “defeat devices”.

In July 2022, the European Court of Justice (ECJ) delivered a seminal judgment pertaining to the classification of “temperature windows” as defeat devices. The applicants in the case alleged that several car manufacturers installed a software (temperature window) in their vehicles which caused the exhaust gas purification systems to work only at outside temperatures between 15 and 33℃, and at a driving altitude of less than 1000 meters. It was alleged a “temperature window” is a defeat device.

The ECJ noted that for a software to be classified as a defeat device, it must reduce the effectiveness of the emission control system “under conditions which may be reasonably be expected to be encountered in normal vehicle operation and use.” The Court determined that the parameters of the “temperature window” found in these vehicles were within reasonable expected conditions that would be encountered as temperatures below 15℃ and altitudes above 1000 meters were normal within the territory of the EU. It was thus also determined by the court that during normal driving conditions the effectiveness of the emissions control system is significantly reduced.

The respondents argued against temperature windows being classified as defeat devices by relying on the exception provided under Article 5(2) of the same Regulation. One such exception is that it was needed to protect the engine against damage for the safe operation of the vehicles. The ECJ however found the “temperature window” only protected the emissions control systems, and not engine itself, from damage and thus does not fall within the exception. The court thus found against the respondents.

Gerard Malouf and Partners have commenced class action proceedings before the Supreme Court of Victoria against Mercedes (Mercedes Benz Australia/Pacific Pty Ltd and Mercedes-Benz Group AG together) regarding similar issues with their engines. 

This document is intended only to provide a summary and general overview on matters of interest. It is not intended to be comprehensive nor does it constitute legal advice. We attempt to ensure that it is current but we do not guarantee its currency. You should seek legal or other professional advice before acting or relying on any of the content.

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