Researchers first raised concerns about Volkswagen diesel emissions in mid-2014, culminating in the disclosure of alleged "defeat devices" installed in nearly 600,000 Volkswagen diesel cars from the 2009-2016 model years. Below is a timeline of major events; we'll update this as the story unfolds.
According to letters sent to VW on Sept. 18, 2015, from the Environmental Protection Agency and the California Air Resources Board, here's a deeper dive on what happened. When the EPA conducts emissions testing, automakers have to disclose "auxiliary emissions control devices," according to the EPA's letter. These AECDs affect a car's emissions system based on situational factors, such as how hard the Used Engine is running or how hot it is. The EPA calls AECDs "defeat devices" only if they reduce the effectiveness of emissions controls outside of testing parameters and are not necessary for safety or Used Engine startup.
Mid-2000s: The problem begins when VW decides to push for diesels in the U.S. in 2005. In developing its EA189 four-cylinder diesel — the basis for both the Generation 1 and Generation 2 diesel Used Engine later cited for emissions cheating — a group of powertrain employees decides that by changing "only a small number of an approximate total 15,000 individual algorithms" in the Used Engine management software, the diesel Used Engine could meet emissions targets "within the budget that was available for the development of the Used Engine management software and without the need to involve superior levels," according to a statement by VW in 2016.
May 2014: Researchers at West Virginia University and the International Council on Clean Transportation publish findings that find "significantly higher in-use emissions" in a 2012 Jetta TDI and 2013 Passat TDI, according to the EPA. (Volkswagen markets its diesel cars as TDI.) Volkswagen tells regulators that the differences amount to technical issues and "unexpected" test conditions. Volkswagen sends then-CEO Martin Winterkorn a notice regarding the ICCT testing, but it's bundled with his weekend memos. It's unclear how much attention it receives.
December 2014: Volkswagen agrees to voluntarily recall its diesel cars to address the emissions issues by recalibrating its first- and second-generation EA189 diesel Used Engine .
May 2015: CARB tests the updated emissions on a 2012 Passat TDI, in a lab and on the road. The agency finds some improvement, but not enough.
July 2015: On July 8, CARB shares its findings with VW. None of the technical issues suggested by the automaker are found to explain CARB's results. Between July 8 and Sept. 3, CARB and the EPA say they will not certify VW's 2016 diesel lineup, a necessary step to put those cars on sale. Only then does VW admit to software irregularities. The automaker discloses that the software calibrations in three separate diesel emissions systems had "a second calibration intended to run only during certification testing," according to CARB.
Sept. 3, 2015: VW admits that the cars were "designed and manufactured with a defeat device to bypass, defeat or render inoperative elements of the vehicle's emission control system," CARB says.
The software uses "dyno" and "road" calibrations that read when an emissions test is being conducted; when the car is not being tested, the "road" calibration dials back the effectiveness of two types of emissions-treatment systems: nitrogen oxide traps and selective catalytic reduction (a urea solution). When dialed back, the systems allow the Used Engine to emit nitrogen oxide levels that are 10 to 40 times the allowable amount by the EPA.
Sept. 18, 2015: The EPA concludes that such software constitutes an AECD defeat device, and says that VW has violated the Clean Air Act. The cars in question should not have been EPA-certified, and the Department of Justice can enforce up to $37,500 in civil fines per vehicle. In total, that means VW could face fines ranging up to $18 billion.
Sept. 21, 2015: VW confirms that it has ordered dealers to stop the sales of all four-cylinder diesel cars, as well as the four-cylinder diesel Audi A3. (Audi is a luxury brand in the Volkswagen Group.) The automaker also confirms a stop-sale order for certified pre-owned cars with the four-cylinder diesel.
Sept. 22, 2015: VW announces that some 11 million diesel cars worldwide have the same "defeat device" software that evades emissions testing. The automaker says it's set aside 6.5 billion euros, or $7.3 billion, to cover the cost of fixing affected cars.
Sept. 23, 2015: Volkswagen CEO Martin Winterkorn resigns, saying in a statement that he's unaware of any personal wrongdoing but accepts responsibility for the crisis. Winterkorn says his resignation clears the way for a "fresh start" at Volkswagen.
Sept. 25, 2015: The EPA announces it plans to spot-check other light-duty diesel vehicles for Clean Air Act compliance. The agency is notifying "all automakers that we are stepping up" oversight, an EPA official says.
Matthias Muller is named Volkswagen CEO. Muller says in a press release, "My most urgent task is to win back trust for the Volkswagen Group — by leaving no stone unturned and with maximum transparency, as well as drawing the right conclusions from the current situation. Under my leadership, Volkswagen will do everything it can to develop and implement the most stringent compliance and governance standards in our industry." Muller will remain chairman of Porsche until a successor is found.
Sept. 27, 2015: Volkswagen launches a consumer site, vwdieselinfo.com, with company statements and answers to frequently asked questions.
Oct. 6, 2015: Volkswagen Group of America returns three awards for TDI clean-diesel versions of its vehicles. In a letter to Editor-in-Chief Patrick Olsen, VW Group of America President and CEO Michael Horn states: "In light of the recent action by EPA concerning our 2.0L TDI vehicles and associated allegations, out of respect for you and your highly influential website, we feel it best at this time to return the 2015 Best Bet Award" for the Jetta TDI and the Eco-Friendly Car of the Year Awards for the Passat TDI in 2012 and 2015.
Oct. 7, 2015: Volkswagen CEO Matthias Muller in an interview announces plans to launch a recall in January of millions of cars around the world involved in the diesel-emissions scandal, saying that the automaker hopes to have all of the vehicles repaired by the end of 2016. The recall does not pertain to the roughly half-million affected vehicles in the U.S., for which no timeline has yet been announced.
Oct. 8, 2015: President and CEO of Volkswagen Group of America Michael Horn appears before the U.S. House Energy and Commerce Committee, withdrawing from emissions-certification consideration suspect 2016 diesel models; those models cannot be sold until certification is obtained. Horn also outlines a general plan to remedy the crisis, hold responsible parties accountable and guard against future breaches of trust. Horn says he thinks affected owners will still achieve their cars’ EPA-rated gas mileage after the fix, but there might be a "slight impact on performance."
Nov. 2, 2015: The EPA announces that additional testing has uncovered illegal defeat devices in Volkswagen’s 3.0-liter V-6 diesel Used Engine as well. Officials issue a notice of violation for six more cars: the 2014 Volkswagen Touareg and 2015 Porsche Cayenne SUVs, plus the 2016 Audi A6 and A8 sedans, A7 hatchback and Q5 SUV. (Porsche, like Audi, is a Volkswagen Group brand.) It’s not immediately clear how the violation impacts sales of those nameplates, all of which have 2016 diesel models on sale.
Nov. 3, 2015: Audi, Volkswagen and Porsche tell dealers to stop selling all six models that the EPA says have defeat devices, plus the Q7 SUV, which also has a 3.0-liter V-6 diesel. It comes even as the automaker expresses confusion over the EPA's conclusions and says its V-6 diesel emissions system is legal.
Nov. 9, 2015: Volkswagen issues a "Goodwill Package" to owners of affected 2.0-liter diesel VWs (plus the Audi A3) with a $500 Visa prepaid card, a $500 credit for dealer services or products and a three-year extension on roadside assistance. Owners must register their cars online and visit a dealership once the package arrives in the mail to activate the benefits. VW says that accepting the package does not preclude owners from future compensation or an eventual vehicle fix.
Dec. 10, 2015: In an update on its internal investigation, Volkswagen says it's uncovered individual misconduct, weak processes and a culture in some parts of the company that "tolerated breaches of rules." VW admitted to a "chain of errors" that began once the automaker decided to push hard for U.S. diesel expansion in 2005 but found that its early diesel four-cylinders wouldn't be able to meet U.S. nitrogen oxide emissions targets under existing budgetary and time constraints.
Jan. 4, 2016: The Department of Justice sues the Volkswagen Group, including Audi and Porsche, for violations against the Clean Air Act for every U.S. diesel vehicle sold since the 2009 model year. Monday's lawsuit covers some 584,000 vehicles. It's "an important step to protect public health," Cynthia Giles, assistant administrator for enforcement and compliance assurance at EPA, says in a statement. "Recall discussions with the company have not produced an acceptable way forward. These discussions will continue in parallel with the federal court action."
Jan. 11, 2016: Volkswagen announces it is extending its $1,000 goodwill offer to owners of 2009-16 Touareg SUVs, which have a 3.0-liter diesel V-6 Used Engine . Previously the payment was only available to owners of vehicles with 2.0-liter diesel four-cylinder Used Engine .
Jan. 12, 2016: The California Air Resources Board rejects Volkswagen's proposed fix for its diesel 2.0-liter Used Engine . The details of the proposal are confidential, but CARB says the plan is too unspecific in its technical changes and how they would impact affected cars. The EPA agrees with CARB.
Feb. 25, 2016: A California judge reportedly orders VW to produce a firm answer by March 24 on whether it has an EPA-approved fix for its diesel cars. VW says it's progressing toward a solution but can't share details on any settlement discussions by order of the Justice Department.
March 9, 2016: Michael Horn steps down as president and CEO of Volkswagen Group of America. Hinrich Woebcken will replace Horn on an interim basis. Woebcken was recently named the head of the North American Region and chairman of Volkswagen Group of America.
March 24, 2016: The California judge overseeing the lawsuits in the Volkswagen diesel crisis grants an extension until April 21 to reach an agreement with regulators on how to fix its diesel cars. The judge cites “substantial progress” by VW and regulators toward a solution, according to the automaker.
March 26, 2016: The Federal Trade Commission files suit against Volkswagen for deceptive advertising in its former "clean diesel" ad campaigns. The FTC claims VW misled consumers and seeks compensation for anyone who bought or leased a diesel car from the automaker between late 2008 and late 2015.
April 21, 2016: Volkswagen, regulators and consumer attorneys present a proposed settlement covering the about 480,000 2.0-liter VW diesels from 2009 through 2016 model years. Owners could sell back the car or have it fixed, plus get cash compensation. The judge sets June 21 for a final plan to be made public that also would settle regulatory penalties and consumer lawsuits. He sets July 26 for a hearing on final approval. Still unresolved is a proposal for fixing the roughly 80,000 3.0-liter V-6 Audi, Porsche and VW diesels.
April 22, 2016: In a postponed announcement of its full-year financial results, Volkswagen Group says it will take a 16.2 billion euro loss ($18.2 billion at current exchange rates) on the diesel crisis, resulting in an after-tax loss of 1.36 billion euros ($1.53 billion) for 2015.
June 15, 2016: Citing the "highly technical nature of the proposed settlements in these complex proceedings," a U.S. district judge extends the deadline for regulators and Volkswagen plaintiffs to file more specifics on a diesel solution to June 28, one week later than the prior deadline.
June 28, 2016: Volkswagen, regulators and plaintiffs' groups announce a settlement of up to $14.7 billion that includes a detailed buyout program aimed at getting 85 percent of four-cylinder TDI vehicles off the road. The most significant point in the program requires Volkswagen to offer owners their cars’ pre-scandal market values plus compensatory bonuses — a total that ranges from $12,475 to $44,176 per car. The settlement also requires Volkswagen to pay nearly $5 billion into two funds to mitigate pollution and invest in environmental technology. The total will cost the automaker up to $14.7 billion, and it doesn't address the diesel V-6 vehicles involved in the scandal or settle investor lawsuits, criminal investigations and pending civil penalties. The California court overseeing the settlement sets a preliminary approval hearing for July 26. Pending its approval, the terms of the settlement can begin to play out.
July 26, 2016: Federal district court gives preliminary approval to the proposed $14.7 billion settlement. Owner notifications will begin immediately and owners can begin the registration process to determine their options and see what the compensation would be for their specific vehicle. The tentative OK also opens a period in which interested parties may raise objections to the deal. The court sets Oct. 18 for a hearing on final approval.
Aug. 25, 2016: At a status hearing in the federal district court in California overseeing the consolidated diesel scandal lawsuits against Volkswagen, U.S. District Judge Charles Breyer pushes the parties to move ahead with talks on a settlement regarding the 3.0-liter V-6 diesels used in VW, Audi and Porsche vehicles, along with continuing to work toward a potential fix for the vehicles. He sets Nov. 3 for the next hearing on the 3.0-liter talks and possible fix. Separately at the hearing, an agreement in principle is announced to settle claims against Volkswagen by its dealers for lost sales and lost franchise value resulting from the diesel scandal. The company says talks with the dealers will continue on final details for a settlement proposal expected in September, which VW says would include "cash payments and provide additional benefits."
Sept. 9, 2016: The Department of Justice announces that James Robert Liang, an Used Engine er who had worked on Volkswagen diesels since the 1980s, has been indicted and pleaded guilty to one count of conspiracy to commit wire fraud, defraud the U.S. and violate the EPA's Clean Air Act. Liang has entered a plea agreement to cooperate with the government's investigation. Citing the agreement, the DOJ says Liang was instrumental in creating the defeat-device software at the heart of the emissions scandal. It's reportedly the first criminal charge to emerge from the DOJ's ongoing investigation.
Oct. 18, 2016: At a federal court hearing in San Francisco, arguments are made for and against final approval for the 2.0-liter diesel settlement proposal that received the preliminary OK in July. Judge Charles Breyer says he is "strongly inclined" to grant final approval but will consider the objections for possible modifications and issue a decision "on or before" Tuesday, Oct. 25.
Oct. 25, 2016: Federal District Court Judge Charles Breyer gives final approval to the 2.0-liter four-cylinder diesel settlement following a hearing on Oct. 18 for objections to the deal. Volkswagen says the buyback process for recalled cars will begin immediately. Negotiations on a recall fix continue and buyers have until September 2018 to decide on the buyback. Talks also continue on a settlement and fix for the 3.0-liter V-6 diesels.
Dec. 20, 2016: The federal court overseeing the diesel scandal announces a preliminary agreement worth more than $1.2 billion among Volkswagen, owners, and federal and state agencies to fix or buy back roughly 83,000 vehicles with the 3.0-liter V-6 diesel Used Engine and contribute to environment remediation. Final details and court approval are expected by spring.
Jan. 6, 2017: Federal and state regulators approve a recall fix for the latest-generation 2.0-liter four-cylinder diesel Used Engine used in model-year 2015 Volkswagen and Audi cars.
Jan. 9, 2017: The FBI arrests a former Volkswagen U.S. regulatory compliance official on fraud conspiracy charges.
Jan. 11, 2017: The Department of Justice and Volkswagen Group announce a $4.3 billion deal to settle civil penalties and a criminal investigation into its actions in the diesel cheating. The deal includes a $2.8 billion fine and guilty pleas to three felonies to settle the criminal investigation and a total of $1.5 billion to settle claims of federal violations by environmental, import and financial regulators. In addition, VW agrees to use an independent corporate compliance monitor for three years and to cooperate in the prosecution of individual employees responsible for the scandal. Five more have been indicted.
Jan. 31, 2017: Volkswagen agrees with regulators and owners to spend about $1.2 billion to buy back older 3.0-liter V-6 diesel vehicles that violate emissions rules and to fix the newer ones, plus give those owners a payment. The proposed deal includes payments of $225 million to an EPA environmental mitigation fund and $25 million to the California Air Resources Board that were agreed to previously. A federal court hearing is scheduled for Feb. 14 for preliminary approval of the deal. A fix has not yet been approved, and if one is not approved, VW will have to offer to buy back all of the approximately 78,000 3.0-liter vehicles in use. The buyback applies to the 2009-12 Volkswagen Touareg and Audi Q7. The potential fix would apply to the 2013-16 Volkswagen Touareg; 2013-2015 Audi Q7; 2014-16 Audi A6, A7, A8, A8L, Q5; 2013-16 Porsche Cayenne.
Feb. 14, 2017: The proposed $1.2 billion deal among Volkswagen Group, regulators and owners to buy back or fix roughly 78,000 Audi, Porsche and Volkswagen 3.0-liter V-6 diesel vehicles is given preliminary approval in federal district court in San Francisco. The proposed agreement, posted here, calls for VW to buy back the older V-6 diesel vehicles and to fix the newer ones (if a fix is approved this year), plus give those owners a restitution payment. A hearing for final approval is set by Judge Charles Breyer for May 11.
April 21, 2017: Regulators give final approval to a criminal fine of $2.8 billion — the bulk of Volkswagen's $4.3 billion settlement announced in January 2017 with the Department of Justice - and appoint an independent compliance monitor and auditor for three years. Volkswagen vows "to cooperate fully" with the monitor, former Deputy Attorney General Larry D. Thompson.
May 11, 2017: Federal Judge Charles Breyer in San Francisco said he will give final approval to the $1.2 billion settlement among the Volkswagen Group, regulators and owners to buy back or fix about 80,000 Audi, Porsche and Volkswagen vehicles equipped with 3.0-liter V-6 diesels. He set May 17 as a deadline a final written order and June 23 for a status report on the deal. Elizabeth Cabraser, lead counsel for the consumer plaintiffs, said in a statement that by May 5, more than 70 percent of the owners had registered for the proposed settlement (posted here), which calls for VW to buy back the older V-6 diesels (VW Touareg and Audi Q7) and fix newer models (Touareg, Porsche Cayenne, and Audi Q7, Q5, A6, A7 and A8) plus pay those owners $7,000 and $16,000. Those also must be bought back if a fix is not approved on schedule. Separately, the judge approved a settlement by Bosch, diesel software supplier, to pay owners and lessors of the 3.0-liter diesels up to $1,500 and up to $350 for the 2.0-liter four-cylinder diesels. VW said in a statement, "We welcome the Court's decision to approve the 3.0-liter TDI V-6 settlement. ... Eligible customers will be notified of any actions they need to take after the written approval order is filed."
May 17, 2017: As required by the court-ordered deadline, a written approval signals that the Volkswagen Group can begin to process the buyback and compensation orders for owners of affected 3.0-liter diesel cars. In a statement, the Federal Trade Commission says today’s order — along with those obtained by the Justice Department and the EPA — conclude the agencies' current litigation against Volkswagen.
May 19, 2017: The Volkswagen Group receives regulatory approval from the EPA and CARB to fix more than 84,000 2012-14 Volkswagen Passat TDI sedans involved in the scandal. In a letter from the agencies, a fix is approved for Gen 2 EA189 diesel four-cylinders with a diesel-exhaust fluid treatment, but only those with automatic transmissions — stick-shift Passats remain unapproved because a fix could not be applied “without negatively affecting important consumer attributes, such as vehicle durability and reliability,” according to the letter.