Key events in the ongoing Volkswagen diesel emissions scandal, taken from law enforcement documents
May 2006: Unable to meet new NOx standards for a new 2.0-liter diesel engine designed for the U.S., VW supervisors and employees decide to secretly cheat the tests with software. The “defeat device” senses when the car is being emissions- tested and alters its output to meet standards during testing. A VW engineer first warns others in an email that the actions are illegal.
November 2006: VW employees brief a supervisor about the defeat device; are ordered “not to get caught.”
March 2014: VW employees first learn of the results of an independent study into VW diesel engines by West Virginia University and commissioned by the International Council on Clean Transportation. In response, VW forms a task force to formulate responses to questions that arise from U.S. regulators. They choose to continue to conceal their use of defeat devices while cooperating.
May 2014: In response to the ICCT study showing a difference between VW diesel emissions during testing and real-world use, the California Air Resources Board requests an explanation from VW.
May 23, 2014: A memo about the ICCT study is prepared for Martin Winterkorn, then VW group CEO, which was included in what the company calls his “extensive weekend email.” VW says it has not been documented as to whether, or how much, Winterkorn took notice of the memo.
Nov. 14, 2014: Winterkorn receives another memo that contains, among other items, information on current product defects and which refers to costs of approximately 20 million euros ($22 million) for the diesel issue in North America.
Summer 2015: VW’s Committee for Product Safety establishes a diesel task force after CARB tests show modified engines still produce excessive levels of NOx.
July 27, 2015: After U.S. regulators threatened not to certify VW 2016 model vehicles for sale in the United States, Oliver Schmidt, a U.S.-based VW executive overseeing certification, and other VW employees discuss the U.S. diesel problems on the sidelines of a regular meeting in Germany about damage and product issues.
Aug. 18, 2015: Supervisors approve a script to be followed by VW employees during an upcoming meeting with CARB in California on or about Aug. 19, 2015. The script calls for continued concealment of the defeat device.
Aug. 19, 2015: During a meeting with CARB, an unidentified VW employee now cooperating with investigators goes against company orders and admits VW has cheated on its emissions testing.
Sept. 3, 2015: VW formally reveals existence of the defeat device to CARB and the EPA during a meeting. Winterkorn is informed in a note, dated Sept. 4.
Sept. 18, 2015: The EPA issues a public notice of violation of the Clean Air Act to VW, alleging that 2009-15 model VW and Audi diesel vehicles with 2.0-liter engines included defeat devices. VW admits to 11 million vehicles affected worldwide.
Sept. 23, 2015: Winterkorn resigns, saying his departure cleared the way for a “fresh start.”
Sept. 25, 2015: VW appoints Matthias Mueller, head of its Porsche unit, as new CEO.
Sept. 9, 2016: A Volkswagen engineer, James Liang, pleads guilty in a U.S. court for his role in rigging emissions software on 2.0-liter diesels sold in the U.S., marking the first criminal charge in the U.S. government’s probe. Liang cooperates and faces sentencing in May 2017.
Nov. 22, 2016: VW says it will stop selling diesel vehicles in the U.S.
Jan. 4, 2017: VW says CEO Mueller will skip the Detroit auto show.
Jan. 7, 2017: Schmidt is arrested in Miami on his way home to Germany from vacation.
Jan. 11, 2017: Six VW executives are indicted, including Schmidt, in U.S. District Court and the U.S. announces the $4.3 billion criminal settlement.