In September 2015, the United States Environmental Protection Agency (EPA) discovered that Volkswagen (VW) cars sold in US had a software programmed to activate emission controls of its diesel engines during an audit.
From 2009 to 2015, VW sold about eleven million cars worldwide installed with the software. During those years, it launched many high-profile marketing campaigns promoting the small emissions of their diesel cars. It also won several environmental awards, including Green Car of the Year awarded to the 2009 Volkswagen Jetta.