Volkswagen Emissions Defeat Device and EPA Scandal Explained: The Truth is in the Software

Volkswagen TDI Clean Diesel ad 1 photo
Photo: VW
I know what you're thinking right now. "What was Volkswagen thinking with the defeat device, trying to trick the EPA and American consumer into thinking that fluffy clouds come out of TDI Clean Diesel-powered cars?" We don't know either, but we can explain to you how the defeat device works.
But first, here's a quick rundown of how it all happened. On Friday, September 18th, the U. S. Environmental Protection Agency mailed this letter here to Volkswagen Group of America, Inc. From it, we find out that the EPA determined that Volkswagen and Audi have "manufactured and installed defeat devices in certain model year 2009 through 2015 diesel light-duty vehicles equipped with 2.0-liter engines." Oopsie!

Commonly known as the TDI Clean Diesel in the United States, the 2-liter oil burner is internally known as the Type EA 189 TDI and it equips just shy of half of million US-spec Volkswagen and Audi A3 models.

Or so we were told... Today, Vee-Dub issued an official statement that informs us about the scale of this calamity (see attached press release). More specifically, the Type EA 189 TDI engine has been fitted to roughly 11 million vehicles worldwide. Do we smell a recall? Not so fast.

While the engine management software is installed on these cars as well, we're told: "for the majority of these engines the software does not have any effect." To boot, we're assured that the Euro 6-complying 2.0 TDI engines currently available in Europe "comply with legal requirements and environmental standards."

That's not the end of this TDI saga, though. Are you ready to find out the next chapter's secret?

"The software in question does not affect handling, consumption or emissions." We're not sure if they're referring to the European-spec 2.0 TDI or the US-spec TDI Clean Diesel, but one thing is certain – if Volkswagen has to recall vehicles with defeat devices, the fix will take its toll on output or fuel economy. Handling doesn't have anything to do with an emissions software. An honorable mention though: Volkswagen's US boss issued a public apology at the launch event of the 2016 Volkswagen Passat, and I'm quoting: "We have totally screwed up" and we "will pay what we have to pay." Now that'll be tricky.

For cheating emissions tests, Volkswagen faces a possible $18 billion fine from the EPA, the maximum penalty. For cars that emit nitrogen oxides (NOx) at up to 40 times the standard during normal operation (as in city and highway driving), this is a harsh possible outcome. Then there's the cost of fixing all of those cars, be it half of million or the entire 11 million population of EA 189 TDI-equipped cars. That won't be cheap either. However, Vee-Dub's hit on the stock market will be more costly to the company.

According to Yahoo! Finance, Volkswagen AG took a hard hit on the stock market. At the time of writing this story, a Volkswagen AG share dropped 32% compared to its value on Friday, September 17th, a day before the manufacturer's "Black Friday" or "Dieselgate." VW shares closed at €161.1 on Friday, then took a dive at €106 at the time of writing, meaning some €26 billion or so has been wiped off the value of the German carmaker this week. It's a hard blow on all fronts, and it's kind of funny because Volkswagen should've known better considering the GM, Toyota, and Takata recalls of recent years. With this small lecture over, let's cut down to the chase - the defeat device and how it's working.

The emissions defeat device

By "defeat device," automotive journalists refer to that little part of code of the software that's programmed into the ECU. As such, we're dealing with a smooth operator, not a physical device. The ECU's "switch software" knows when a car is plugged in for emissions testing, the moment when it changes to "See how green I am? I emit unicorns and rainbows!" The software algorithm is programmed to filter all the mucky stuff coming from the engine as long as the car is undergoing official emissions testing, turning full emissions control on only during the test.

But after that, the car leaves the testing facility. Then Johnny Muck comes on the scene, with the software switching into "Woohoo! We did it! Now let's kick NOx levels up, yo!" In basic English, that translates to reducing the selective catalytic converter's efficiency. As noted beforehand, when the vehicle is normally operated, the ECU switches into a mode that doesn't filter NOx to the levels advertised by Volkswagen.

The factors analyzed by the software are barometric pressure, duration of engine operation, and speed. When there no EPA guy around, the ECU switches to the so-called "road calibration" mode, which is up to 40 times more NOx-laden than the clean "dyno calibration" mode recognized when taking an emissions test.

Playing hide and seek with the EPA and nitrogen oxide levels isn't something to laugh about. At the present moment, the story is still unfolding, with the EPA and the German Federal Motor Transport Authority investigating the matter. Mind you, this isn't the first time the EPA caught a manufacturer red-handed.

Back in 1998, the EPA caught Caterpillar, Cummins, Detroit Diesel Corporation, Mack Trucks, Navistar International, Renault Vehicles Industriels, and Volvo Truck doing pretty much the same thing. The companies were forced to spend $1 billion in settlements for their emission test-bypassing trucks, including an $83.4 million civil penalty. At the time, it was the largest ever violation of environmental law in the US.

If you own a 2.0 TDI Clean Diesel Volkswagen or Audi, would you mind telling us what's your position on this one? If you don't, we're curious to find out if this scandal is more serious to you than the shameful (and potentially deadly) tricks General Motors, Toyota, and Takata played on us in recent years.
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 Download: Volkswagen Notice of Violation for Emissions Defeat Device from US EPA (PDF)

Press Release
About the author: Mircea Panait
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After a 1:43 scale model of a Ferrari 250 GTO sparked Mircea's interest for cars when he was a kid, an early internship at Top Gear sealed his career path. He's most interested in muscle cars and American trucks, but he takes a passing interest in quirky kei cars as well.
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