At the beginning of November, the EPA issued its second notice of violation against the Volkswagen Group, claiming that 2014, 2015 and 2016 model year cars powered by the company's 3.0-litre turbo-diesel V6 engines were fitted with a defeat device, which allowed it to illegally pass American emissions testing for NOx (oxides of nitrogen).
The EPA says that if the engine's control software detects an emissions test, it enters a "temperature conditioning" mode that limits the output of NOx. When it believes that the test is over, the engine reverts to operating in its regular configuration, emitting up to nine times the permitted levels of NOx.
According to Automotive News, the Volkswagen Group told the EPA this week that the same software was used on its 3.0-litre V6 TDI engines from the 2009 model year onwards.
This brings the total number of affected vehicles in the USA up to around 85,000.
Jeri Ward, head of communications for Audi America, explained to the industry publication that the software used in the V6 TDI engine is compliant with European emissions regulations. He also stated that the company did not inform the EPA about the software, and that the EPA considers it to be a form of defeat device.
Ward told Automotive News: "We are fully cooperating with the environmental authorities and working on concrete measures that will resolve this situation. We’ll need some software changes in the future that will ultimately resolve this and there are more discussions that will be needed with the agencies.”
Volkswagen, Audi and Porsche have halted sales of cars with the cited 3.0-litre V6 turbo-diesel engine in the US.
More: All the news related to Volkswagen's dieselgate affair.