ORNL researchers using additive manufacturing for advanced traction motor prototyping
Porsche Cars North America says it was “surprised” to receive EPA NOV on emissions

EPA issues a second notice of violation to Volkswagen alleging emissions cheating in MY 2014-2016 3.0L diesels (Updated with VW response)

EPA issued a second notice of violation (NOV) of the Clean Air Act (CAA) to Volkswagen AG, Audi AG and Volkswagen Group of America, Inc., alleging emissions cheating. This NOV is also being issued to Porsche AG and Porsche Cars North America. In response, VW AG in Germany issued a statement asserting that “no software has been installed in the 3-liter V6 diesel power units to alter emissions characteristics in a forbidden manner.” Volkswagen said it will cooperate fully with the EPA to “clarify this matter in its entirety.”

The NOV alleges that the VW Group companies developed and installed a software defeat device—specifically, code in the electronic control module (ECM)—in certain VW, Audi and Porsche light duty diesel vehicles equipped with 6-cylinder, 3.0-liter engines for model years (MY) 2014 through 2016 that results in increased NOx emissions of up to nine times EPA’s standard. The vehicles covered by the new NOV are the diesel versions of the 2014 VW Touareg, the 2015 Porsche Cayenne, and the 2016 Audi A6 Quattro, A7 Quattro, A8, A8L, and Q5.

EPA and the California Air Resources Board (CARB) have both initiated investigations based on Volkswagen’s alleged actions. The NOV covers approximately 10,000 diesel passenger cars already sold in the United States since MY 2014. In addition, the NOV covers an unknown volume of 2016 vehicles.

These alleged violations are in addition to the NOV issued on 18 September and the ongoing investigation by EPA alleging a defeat device on certain 2.0-liter engines for MY 2009-2015 vehicles. (Earlier post.)

Following the 18 September NOV issued for 2.0 liter engines, on 25 September EPA initiated testing of all 2015 and 2016 light duty diesel models available in the US using updated testing procedures specifically designed to detect potential defeat devices. That testing led directly to the alleged violations covered under today’s NOV. The NOV is based on vehicle emission testing performed by the EPA’s National Vehicle and Fuel Emissions Laboratory, CARB’s Haagen-Smit Laboratory, and Environment Canada’s River Road Laboratory.

When this software determines the vehicle has begun the FTP 75 Federal emission test procedure, it directs the vehicle to employ a low NOtemperature conditioning mode. A status bit in the software indicates that a “temperature conditioning” mode is active. In this low NOtemperature conditioning mode, the vehicle operates under a number of emission control parameters, including injection timing, exhaust gas recirculation rate, and common rail fuel pressure in such a way that the parameters yield low engine-out NOx emissions and high exhaust temperatures. The high exhaust temperature heat the selective catalytic reduction system (“catalyst”) and improve the catalyst’s ability to reduce tailpipe NOx emissions. In this low NOx temperature conditioning mode, the combination of low engine-out NOx and improved catalyst performance results in tailpipe NOx emissions that are below the applicable emissions standard.

However, the software employs a “timer” that coincides with the low NOx temperature conditioning mode. At exactly one second after the completion of the initial phases of the FTP 75 Federal emissions test procedure (1,370 seconds, which is when the vehicle would normally be turned off), this software directs the vehicle to cease low NOx temperature conditioning mode. The “temperature conditioning” status bit switches to zero, and a second status bit indicates the activation of “transition to normal mode.” In this “normal mode,” the emission control system is immediately less effective. Compared to the low NOx temperature conditioning mode, the vehicle employs a different injection timing, exhaust gas recirculation rate, and common rail fuel pressure. This yields higher levels of NOx from the engine and reduced exhaust temperatures.

In addition, when the vehicle starts under conditions that the software determines are not the beginning of the FTP 75 Federal emission test procedure, the vehicle does not use the low NOx temperature conditioning mode at all. Instead, the emission control parameters are set consistent with the “normal mode.”

In sum, as soon as the vehicle senses that it is not being tested, it used “normal mode.” In “normal mode,” tailpipe emissions of NOx are up to 9 times the applicable NOx standard levels, depending on model type and type of drive cycle (e.g., city, highway).

—EPA 2 November NOV

VW’s software on these vehicles includes one or more Auxiliary Emission Control Devices (AECD) (earlier post) that the company failed to disclose, describe and justify in their applications for certificate of conformity for each model, EPA said. (AECDs are not prohibited, but they must be disclosed.) Every manufacturer must apply to EPA for and be approved for a certificate of conformity for each model, each year otherwise it is illegal to introduce the cars into commerce. An AECD designed to circumvent emissions test is a defeat device.

In his prepared testimony for the House Committee on Energy and Commerce Subcommittee on Oversight and Investigations hearing in October, Michael Horn, President and CEO of Volkswagen Group of America, said that VW’s emissions control strategy also included a software feature that should have been disclosed to and approved by the agencies as an auxiliary emissions control device (“AECD”) in connection with the certification process. As a result, Horn said, Volkswagen withdrew the application for certification of its model year 2016 vehicles. The company was working with the agencies to continue the certification process, he added.

The Clean Air Act requires vehicle manufacturers to certify to EPA that their products will meet applicable federal emission standards to control air pollution, and every vehicle sold in the US must be covered by an EPA-issued certificate of conformity. The Clean Air Act also prohibits manufacturers’ making and selling vehicles equipped with defeat devices that reduce the effectiveness of the emission control system during normal driving conditions. By making and selling vehicles with defeat devices and by selling vehicles with higher levels of air emissions than were certified to EPA, Volkswagen allegedly violated two important provisions of the Clean Air Act.

VW may be liable for civil penalties and injunctive relief for the violations alleged in the NOV. VW will have an opportunity to respond to the allegations contained in the NOV.

It is Volkswagen’s responsibility to fix the vehicles’ emissions systems, EPA said. Although these vehicles have emissions exceeding standards, these violations do not present a safety hazard for car owners and drivers and the vehicles remain legal to drive and resell. Owners of vehicles of these models and years do not need to take any action at this time.


Michael B.

Boy oh boy, the proverbial fan is being pummeled, and that NOxious stuff is getting all over the place!

Nick Lyons

Who is in charge at VW? How can this be happening? Worst crisis management ever!

Account Deleted

This was already insane and it is getting worse. VW needs to appoint a new CEO that is not from VW. There are no high level managers left in VW that cannot be under strong suspicion of knowing about this and therefore also participating in this fraud scheme. It is as serious as it gets because it causes mass murder by increasing the cases of premature death caused by the air pollution from these over 10 million cars that VW has delivered with this system.

However, the scandal is much larger than over 10 million VWs polluting as much as 500 million cars. In Denmark it has been revealed that most auto repair shops illegally offer either so called 1) chip tunes or 2) hardware "fixes" that both disable the entire exhaust system in order to achieve better fuel economy and horsepower. It only cost about 200 USD and take a few minutes. There are no authorities in Denmark that control the emissions from cars that has been sold. The hole emission test system is completely dysfunctional and it is the lobbyist from the European car industry that has twisted the legislation in a that direction.

Very few politicians want to do anything about it because they get their donations for looking the other way and passing legislation that sidestep the environment and the health of people.

I do not think Denmark is the only European country where you can have your local euro repair shop disable the entire exhaust system for a few dollars (euro). It must be happening throughout Europe and be the key reason that the air pollution levels are sky high in European cities and seems to get worse every year.

About auto repair shop disabling of emission system using hardware changes (in Danish)

About auto repair shop disabling of emission system using chip tunes (in Danish)

WHO on 7 million premature air pollution death per year globally.


This was not something done by Bosch nor in house programmers, it was a way to make more money. VW said they were going to make a push in the U.S. then beat Toyota, this was the money to do that.


Managers were suppose to look the other way, now they are being fired for looking the other way.


It can't be just VW. When will the others be found out (officially) too?

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