[43] In January 2017, Volkswagen pleaded guilty to criminal charges and signed an agreed Statement of Facts, which set out how the company's management asked engineers to develop the defeat devices, because its diesel models could not pass US emissions tests without them, and deliberately sought to conceal their use.

The scandal raised awareness over the higher levels of pollution emitted by all diesel-powered vehicles from a wide range of car makers, which under real-world driving conditions exceeded legal emission limits.

[56][59] Volkswagen chose the "lean NOx trap" system for its turbo-diesel Golf and Jetta models, but the solution did not work well as it required a fuel-rich exhaust gas in the purification process and fuel economy suffered as a result.

During this meeting at the end of February 2015, Primor introduced Piëch to his friend Yuval Diskin, who after retiring from directing the Israeli secret service of the Interior Shin Bet, had founded a cybersecurity company.

"[127] Olaf Lies, a Volkswagen board member and economy minister of Lower Saxony, later told the BBC that the people "who allowed this to happen, or who made the decision to install this software" acted criminally, and must be held personally accountable.

[9][140] In November 2016, California regulators claimed to have discovered software installed on some Audi models that allowed the manufacturer to cheat CO2 emissions during standard testing, thereby also masking the cars' contribution to global warming.

[177][179] In the United States, Volkswagen withdrew its application for emissions certification for its 2016 diesel models, leaving thousands of vehicles stranded at ports in October 2015, which the company said contained software which should have been disclosed to and certified by the EPA.

The High Court of Justice had giving preliminary findings in the case in April 2020 that there is a likelihood that Volkswagen did sell vehicles with a "defeat device" and attempted to abuse the process, allowing the trial to go forward.

[227] Ontario provincial authorities executed a search warrant at Volkswagen Canada offices in the Toronto area on 19 September 2017[228] as part of its investigation into the emissions scandal that rocked the company two years ago.

The Ministry of the Environment and Climate Change have charged Volkswagen AG with one count under the province's Environmental Protection Act, alleging the German company did not comply with Ontario emission standards.

[239] On 27 October 2015, the European Parliament voted a resolution urging the bloc to establish a federal authority to oversee car-emissions, following reports in the press that top EU environmental officials had warned, since early 2013, that manufacturers are tweaking vehicles to perform better in the lab than on the road.

[241] In December 2015, the EU Parliament voted to establish a special of inquiry committee to investigate whether regulators and executive officials, including the European Commission, failed to oversee the car industry and its pollution testing regimes.

[242] In June 2016, documents leaked to the press indicated that in 2010, European Commission officials had been warned by their in-house science team that at least one car manufacturer was possibly using a NOx-related defeat device in order to bypass emission regulation.

[271] In May 2016, Norway's sovereign wealth fund, the world's largest ($850 bn) and also one of the company's biggest investors, announced legal action against Volkswagen, to be filed in Germany as part of a class-action lawsuit being prepared there.

The Select Committee published a letter from Paul Willis, managing director of Volkswagen Group UK Ltd of 21 December 2015 stating: "In very simple terms, the software did amend the NOx characteristics in testing.

The complaint, seeking up to $46 billion in penalties for Clean Air Act violations,[298] alleged that Volkswagen equipped certain 2.0 and 3.0-litre diesel-engine vehicles with emissions cheating software, causing NOx pollution to exceed EPA's standards during normal driving conditions.

[298] On 12 January 2016, US regulators rejected Volkswagen's recall plans for its affected 2.0-litre diesel engines, submitted to CARB in December 2015, claiming that these "do not adequately address overall impacts on vehicle performance, emissions and safety".

[317] Toward that end, Volkswagen formed a U.S. subsidiary called Electrify America, LLC., based in Reston, Virginia, that will manage the $2 billion brand-neutral zero-emission vehicle infrastructure programs and marketing campaigns for the next ten years.

[333] On 19 November 2015, ABC News Australia reported that more than 90,000 VW, Audi and Skoda diesel vehicle owners had filed a class action lawsuit against Volkswagen in the country's Federal Court.

[341] Later the same month, German investor group DSW called for an independent audit of Volkswagen's emissions-cheating practices, arguing that the company's internal investigation might not necessarily make everything transparent to smaller shareholders.

[167] In the case of 3.0-litre V6 TDI engines, Volkswagen suggested it can provide an uncomplicated fix that will bring the vehicles into compliance without adversely affecting performance, a move that the company hopes will avoid an expensive buyback of these cars.

[348] In January 2016, documents obtained by CEE Bankwatch Network provided more details for a European Investment Bank statement that its loans to Volkswagen may have been connected to the car makers use of cheating devices to rig emission tests.

[373][374] In South Korea, sales in November rose 66 percent to 4,517 units from a year ago due to the Volkswagen's aggressive marketing efforts such as a discount of up to ₩18,000,000 (US$15,600 at December 2015 exchange rates) for some models.

Müller stated that the changes would "require us – following the serious setback as a result of the diesel issue – to learn from mistakes made, rectify shortcomings and establish a corporate culture that is open, value-driven and rooted in integrity".

Some of the manufacturers accused include: Toyota,[396][397] Suzuki,[398] BMW,[399] Citroën and Peugeot under PSA[400] (now a part of Stellantis), Mitsubishi,[401] Nissan and Renault,[402] Chevrolet and GMC,[403] Ford,[404] Cummins,[405] as well as Hyundai and Kia.

[424] Catherine Bearder, MEP for South East England, commented on 27 October 2015 in the European Parliament that "we now have the political momentum for a radical overhaul that will ensure carmakers cannot dodge the rules", defending an EU resolution meant to specifically "cut deadly pollution from diesel vehicles".

[430] Car and Driver similarly emphasized Volkswagen's inability to efficiently operate in the US market, while also suggesting that the company had grossly underestimated the EPA's power, and inexplicably failed to go public before the story broke, despite receiving ample warning.

[431] Tesla Motors CEO Elon Musk was asked about his opinion whether the scandal will weaken the consumer's view on green technologies; he responded saying he expects the opposite to happen: "What Volkswagen is really showing is that we've reached the limit of what's possible with diesel and petrol.

"[432] Similarly, analysts at Fitch suggested the Volkswagen diesel emissions crisis was likely to affect the entire automotive industry, with petrol cars potentially enjoying a revival in Europe and greater investment being poured into electric vehicles.

[435][436] Similar requests were put forward by the American Lung Association, who petitioned the EPA to determine Volkswagen to promote zero-emissions vehicles, build sustainable transport infrastructure and retrofit older diesel models with superior emissions controls.