The investigation will focus on whether fraud was committed through the sale of diesel-powered vehicles equipped with technology that cheats emissions tests.
The Frankfurt Auto Show is said to be the world's biggest. It's usually a showcase for the German car industry. But this year's event is being overshadowed by the VW emissions scandal.
Arvind Thiruvengadam and colleagues at WVU got excited when they won a grant in 2012 to test emissions on a few diesel cars. He figured the data might result in some papers a few people might read.
The software that the EPA says causes Volkswagen cars to cheat official emissions tests exists in only one type of diesel engine, the carmaker says — and it has sold 11 million of them.
"I personally am deeply sorry that we have broken the trust of our customers and the public," says CEO Martin Winterkorn. The company lost nearly a quarter of its market value Monday in Europe.
The agency says some 480,000 diesel-powered Volkswagens have sophisticated software that detects emissions testing — and "turns full emissions controls on only during the test."
The automaker said the new policy would allow dialogue — but not collective bargaining — with groups. It comes months after the UAW lost a vote to represent workers at the Chattanooga, Tenn., factory.