Currently reading: Dieselgate: European Court of Justice deems VW 'defeat devices' illegal
Court rules German car maker’s emissions devices cannot be justified on the grounds of engine maintenance

The European Court of Justice has ruled the software used by Volkswagen to control emissions testing 'defeat devices' is illegal under European law.

In a decision predicted to have wide-ranging ramifications for the ongoing class action lawsuits brought against Volkswagen, as well as other European car makers such as Audi and Mercedes-Benz parent company Daimler, Europe’s highest court sided with purchasers of Volkswagen diesel vehicles who claimed they were deceived into believing their vehicles produced significantly fewer emissions than they actually do in real-world driving conditions.

Following up on an initial ruling handed down in April 2020, Europe’s highest court said diesel emission defeat devices cannot be justified by the argument that they “contribute to preventing the ageing or clogging-up of the engine”.

Volkswagen had argued in favour of a restrictive interpretation of the law, which would have limited the definition of a defeat device to any technologies and strategies operating 'downstream' of the engine (namely, after the production of exhaust gases).

However, the European Court of Justice ruled that the law should also apply to 'upstream' technology, which by definition also includes software used to manipulate diesel exhaust emissions under test conditions.

Such software “must allow the engine to be protected against sudden and exception damage” and “only those immediate risks of damage which give rise to a specific hazard when the vehicle is driven” should justify its use, the court’s ruling said.  

The ruling is expected to result in industry-wide changes to how diesel exhaust emissions are controlled. Software functions known as thermal windows, where the filtering of exhaust gas is lowered or shut down completely to protect engine components at a certain ambient temperature, are used widely by many European car makers.

The ruling also opens the door to the spectre of record recalls and a widening of lawsuits.

Owners of certain diesel Volkswagen models have already brought multiple lawsuits against the German car maker, claiming a loss of value after diesel emission manipulation was exposed by US regulators in September 2015 in a scandal that has so far cost Volkswagen more than €30 billion (£27 billion). 


Inside the industry: five years on, Dieselgate still resonates

Dieselgate: Volkswagen loses appeal over UK group action lawsuit

Four ex-Audi executives charged with fraud over Dieselgate​

Join the debate

Add a comment…
Cobnapint 18 December 2020
Well, better late than never from the ECJ there.
Jeremy 17 December 2020

I wouldn't buy another VW group car either, not just because of dieselgate but because the last one I bought (new) needed a new engine after 60,000 miles. Is it only German diesels that had dodgy software? 

Peter Cavellini 17 December 2020


     Why put the device on there in the first place?, why couldn't they produce a compliant engine design?, was it just to be first to market with these engines? , we've been here before about this, VW were found negligent, and VW thought they could limit the financial backlash by rewording the judgement against them?, well, now, the final decision has been made, no ifs, no buts, pay up VW.

Antony Riley 18 December 2020

So here is the proof .This Lying and cheating company German may I remind everyone has been found to have  lied and cheated to  authoroties and their buying public about their emission levels on all their brands So we have V W, Audi Porsche, Seat and Skoda being found guilty of shameful practices. Yet the buying public still buy from them  WHY. Autocar also has at times  while taking their advertising revenue with open arms have not been strident enough as a car magazine in condeming them . Why I ask Autocar Why. So now the big legal disscusions will now follow to refund millions of people that VAG have cheated on. Remembet they as a  group still have some top brass in custody for allowing said  emission scandal to go on in an attempt that no one would find out. Huuh such low tatics being allowed to proceed should be met with Dont buy  from them Simples