The news media is full of sound and fury regarding something that Volkswagen did with diesel engine emissions control software, e.g., “VW Is Said to Cheat on Diesel Emissions; U.S. to Order Big Recall” (nytimes). The journalists either can’t or don’t bother to explain what Volkswagen actually did.
Readers: Can you help explain this? What does the software in question control? The Times says “The Environmental Protection Agency accused the German automaker of using software to detect when the car is undergoing its periodic state emissions testing.” What does this mean? Only when something is plugged into a connector under the hood? Then “During normal driving situations, the controls are turned off, allowing the cars to spew as much as 40 times as much pollution as allowed under the Clean Air Act, the E.P.A. said.” Can this be true? What is there in a VW that can cut or increase pollution by 40X?