Deutsche Umwelthilfe started a legal proceeding against Germany challenging the software’s authorization before the Administrative Court in Schleswig-Holstein, contending that the approved temperature window constituted a defeat device prohibited by the law of the European Union (EU law). The administrative court decided that Deutsche Umwelthilfe lacked standing to bring the challenge under German law. The court asked the Court of Justice of the EU (ECJ) in a preliminary reference whether the environmental organization might have standing based directly on EU law, in particular the Aarhus Convention on access to information, public participation in decision-making, and access to justice in environmental matters, read in conjunction with the Charter of Fundamental Rights of the European Union. The administrative court also ruled that the temperature window constitutes a defeat device but asked the ECJ whether the window can be justified under the exception in Regulation No 715/2007 that “the need for the device is justified in terms of protecting the engine against damage or accident and for safe operation of the vehicle.”
On November 8, 2022, the ECJ answered that an administrative decision relating to EC type-approval, which may be contrary to EU law, falls within the material scope of Article 9(3) of the Aarhus Convention, since it constitutes an act of a public authority that is alleged to contravene the national environmental provisions. An environmental association has standing under Article 9(3) of the Aarhus Convention if it meets the conditions under national law to bring legal proceedings. The ECJ also notes that member states must comply with the right to an effective remedy, enshrined in Article 47 of the Charter, when establishing the applicable procedural rules. Member states cannot impose criteria so strict that it would be impossible for environmental associations to challenge the acts or omissions that are the subject of the Aarhus Convention. The ECJ concluded that Article 9(3) of the Aarhus Convention, read in conjunction with Article 47 of the Charter, precludes a situation where such an association is unable to challenge a decision granting or amending EC type-approval which may be contrary to EU law. A defeat device can be justified by a need to protect the engine against damage or accident and for the safe operation of the vehicle. The ECJ held that such a justification only exists if the device strictly meets the need to avoid immediate risks of damage or accident to the engine of such a serious nature as to give rise to a specific hazard when a vehicle fitted with that device is driven. The need for such a defeat device exists only if no other technical solution makes it possible to avoid the above mentioned risks. The opposite conclusion could result in the exception being applied more frequently than the prohibition and would result in a disproportionate infringement of the principle of limiting nitrogen oxide (NOx) emissions.