EPA caught VW cheating - how does the car know it's being tested?

Why is it called a dyno if it's spelled dynamometer? Why not call it a dyna?

Reply to
Alina Popescu
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This article says the whole TDI Clean Diesel campaign is a fraud. I don't drive a diesel.

What was the "TDI Clean Diesel" campaign anyway?

Reply to
Danny D.

Oopops. Forgot to include the url:

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What was this "TDI Clean Diesel" campaign anyway? And, what does that have to do with "urea" injection?

How does this UREA injection work?

Reply to
Danny D.

Apparently a way to avoid the urea injection everyone else used to get emissions down to the legal limit.

Both are supposedly ways to meet emissions standards. One works. The other is Wizard of Oz engineering apparently.

A youtube explanation:

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I didn't watch it and ain't qualified to say if it's correct.

Have you noticed signs at truck stops saying "DEF Sold In All Lanes"? That's diesel exhaust fluid or urea.

Reply to
Dean Hoffman

Mechanics are unable to spell and can seldom pronounce words with more than one syllable?

Reply to
Chuck Yew

It's in the article:

All the other carmakers control diesel emissions by spraying a urea solution into the exhaust stream, where a catalyst converts it to ammonia. The ammonia breaks down NOx into nitrogen and water.

Reply to
Dan Espen

I have seen a suggestion that the onboard computer takes note of the fact that the rear wheels are rotating and the front wheels are stationary. That seems plausible to me.

Reply to
Jack Myers

They didn't explicity mention that, but this article has a section named How did this alleged cheat work exactly?

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Reply to
Sam Wilhelm

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(4) What exactly did VW do?

Volkswagen has admitted that it equipped the control software for its

2.0-liter TDI diesel vehicles with a "defeat device" that detected when the car was undergoing emissions testing and significantly changed the operations of its powertrain to reduce emissions during the tests.

That detection was likely based on a combination of sensor data from the car, which might include steering angle (since cars on dynamometer tests don't make turns), front-wheel versus rear-wheel rotation speed, and a variety of other factors.

It appears that a combination of the factors above plus extremely gentle acceleration and braking might alert the car that it wasn't on the road but being tested in a lab.

Reply to
Jack Black

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Based on discussions with knowledgeable sources, we surmise that once an emissions test was detected, VW got the affected TDI engines to meet the Tier 2, Bin 5 NOx limits by reducing the fuel flow rate.

This would reduce performance, but most likely not to the point where the car couldn't complete the emission cycles.

Lowering fuel flow would also reduce combustion temperatures and/or the duration of high-temperature operation enough to keep NOx emissions barely within EPA limits.

If the car detected that it was no longer in "testing mode" but had returned to "driving mode," it would restore fuel flow to the regular level--which would send NOx emissions soaring.

Reply to
Jack Black

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Reply to
Jack Black

VW manufactured and installed software in the electronic control module (ECM) of these vehicles that sensed when the behicle was being tested for compliance with EPA emission standards. For ease of reference, the EPA is calling this the "switch".

The "switch" senses whether the vehicle is being tested or not based on various inputs including teh position of the steering wheel, vehicle speed, the duration of the engine's operation, and barometric pressure.

These inputs precisely track the parameters of the federal test procedure used for emission testing for EPA certification purposes. During EPA emission testing, the vehicle's ECM ran software which produced compliant emission results under and ECM calibration chart that VW referred to as the "dyno calibration".

Reply to
Jack Black

The big remaining question that hasn't been answered is if they can meet the EPA requirements on the dyno test by turning the emissions controls on and/or re-tuning the car, why didn't they just leave it on? I'm guessing it must have affected MPG or performance? The other interesting thing is that when I first heard this, I thought the difference must be some small margin, 10% maybe. According to the news last night, the difference is 10x to 40x?

Sure looks like they are in deep doo doo.

Reply to
trader_4

On Mon, 21 Sep 2015 21:07:31 -0700, "Jack Myers" wrote in

That's the most feasible, i.e. simple, approach to designing the bypass firmware algorithm that I've seen.

Reply to
CRNG

Well the opposite for most or all VWs, but that makes sense.

Reply to
sms

Seems to me that's a failed algorithm. Aren't these cars front wheel drive, ie he has it backwards? Heard on the news last night mention of the steering wheel remaining stationary was an input used too.

Reply to
trader_4

| > My question is HOW did the car *know* it was being *tested* for emissions? |

I'm more curious about how the EPA didn't figure it out earlier. Reports say the EPA saw a discrepancy between testing and on-road results. But they've been haggling with VW all this time and somehow never thought to look at the software. Is the software accessible to EPA? Do they have developers who could understand it?

How the test is faked is just a technical issue. How the EPA didn't figure it out seems to be the important issue. They only found out because they threatened to hold up sales and at that point the VW execs admitted what they were doing. (Have they disclosed everything? Surely if there's more dirty dealing they're not going to tell if they don't have to.)

... Then of course there's the question that begs to be asked: How could all of those executives, in a company whose clientelle tend to be liberal environmentalists, have possibly decided it was a good idea to be so dishonest and shortsighted?

There should be arrests. Either way, it's likely to be a serious, perhaps fatal, blow to the company. If it were Chevy I'm sure rednecks would come out of the woodwork to support "the company that denies global warming". But VW customers are almost a cult following, and mostly liberal.

Reply to
Mayayana

Should there have been arrests of EPA miscreants (or the environmentalists that petitioned them to do so) for the hatchet job they did on DDT? This resulted in millions of third-world deaths from malaria due to other countries following our lead:

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Reply to
Roger Blake

No. The software is a black box both to vehicle owners and the EPA. Not only that, but under the DMCA it would be illegal for vehicle owners OR the EPA to attempt reverse-engineering it from the object load.

Gaming the system is a longstanding tradition among car manufacturers and I am _sure_ that if the source code were made public that all manner of interesting games would be found.

THAT is the best question of all, yes. But that is a question that needs to be asked by stockholders, and I have a suspicion that the next annual meeting at Volkswagen will be interesting.

Arrests will do nothing. What has to happen is that vehicle control code needs to be documented and available to the vehicle owner and to the government inspectors. Yes, I know this makes it easier for technology to be stolen in places where patent and trademark law is unenforced (such as China, where the car industry is growing by leaps and bounds and trying to learn as much as possible from Western and Japanese manufacturers by any means possible). But, it's necessary.

If you want to see something REALLY evil, take a look at John Deere's take on their proprietary control systems. THERE are some people who could use arresting.

--scott

Reply to
Scott Dorsey

This article is not exactly accurate.

In the fifties, DDT was amazing, it worked great. We put it between our sheets. You could spray it in the air and see insects dropping out right and left.

But... by the seventies, mosquitoes (at least in Hawaii where I lived) had pretty much become immune to the stuff. Enormous, absolutely enormous amounts were necessary to kill insects. This is why there were environmental effects. My father had a gadget that would drop a mix of diesel and DDT into the muffler of the lawnmower and the smoke would kill mosquitoes, but by the seventies it wasn't killing them any more, even with a couple pounds of the stuff being burned.

Give it another forty years or so and we might be able to start using DDT in a small way again. But it was the massive overuse and abuse of DDT that got us to the point where it was banned, not some crazy left-wind conspiracy.

And yes, it WAS one of the big weapons in the fight against malaria, and it was a crime to lose that weapon. But it wasn't politicians that lost it.

--scott

Reply to
Scott Dorsey

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