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

Well in California they definitely check via the OBD-II port. I had replaced a battery and there were no dashboard lights indicating anything. The first thing they did was to do a scan for codes.

The number of pending codes that is allowable varies by year of manufacture. A good shop will tell you the drive sequence to clear the pending codes for each model. A bad shop won't even know this information.

In California, one "smog check factory" in L.A. got caught because the state checked registered addresses of the vehicles and wondered why so many vehicles were being smogged at this one particular shop when their registered address was so far away. Few people will drive 25 miles in L.A. to get a smog check at a particular shop.

My brother-in-law regularly had inspectors come into his shop with test vehicles to be smogged. They would reveal who they were after the test. He did really well. He got one demerit for not telling the "customer" that they had the option of getting the vehicle repaired at his shop or any shop, even though he did ask if they wanted it to be repaired. But he still passed the inspection.

Actually it is not pending codes that are the issue. It is the readiness monitors.. Can't remember how many readiness monitors there are - but there's a catalyst monitor, a O2 sensor monitor, and EGR monitors, and O2sensor heater and cat heater monitor on some vehicles. These are the intermittent monitors that need to be "set" .

Setting the monitor just means they have been through one or more test sequences and have aquired valid data..

The rest of the monitors are contimuous monitors - misfire, component, and fuel system, nonitors.

The evap monitor, for instance, is only "valid" in a fixed temperature range, and with the tank between something like 1/4 and 3/4 full (not

100% sure of the actual numbrs). If you reset the codes or replace the battery on a vehicle with the tank full or almost empty you can NOT set the readiness monitor for the evap system - so virtually ALL OBD2 based emission test facilities will allow at least one monitor to be un-set or not ready.

If you know what code is coming up, and want to "cheat" the system, if you can avoid setting that particular monitor, while setting all the others, you can sometimes get a vehicle to pass. You need to understand the drive cycle and what can cause the monitor you want dissabled to fail to set. (and it needs to be an intermittent or non-continuous monitor. The usual culprits are Cat, evap, or EGR.

It's usually documented as the FTP.

That answers what. But it doesn't answer HOW.

Finally!

Someone who both understood the question, and who posited an answer!

Of all the posters, you're the ONLY one who understood the question!

Sofa Slug wrote in mtn6qu$2in$ snipped-for-privacy@dont-email.me:

What I'm surprised at is that each state can have a *different* procedure.

In California, they use the dyno, but in many less technical states, they still use the dumb procedures.

This explains how they noticed there was testing going on.

But that only works for the intelligent states. How did they also fool the low-tech states like NJ, Kentucky & Kansas?

The best answer to the question seems to be here, as noted by Sofa Slug:

"How can the program tell the difference? By noting the position of the steering wheel, variations in speed and other data that suggest no one is driving the car, and thus it is likely being tested."

Apparently VW lied at first, & apparently they can no longer sell the cars:

"The cheating came to light when the California Air Resources Board and the EPA pressed Volkswagen for an explanation for disparities found between lab tests and road tests of its vehicle emissions. The agencies didn't find the technical reasons offered by VW to be convincing and said they would not issue certificates allowing 2016 models to be sold until the automaker offered an adequate explanation. "Only then did VW admit it had designed and installed a defeat device in these vehicles," the EPA said. VW said it was cooperating with the investigation but otherwise had no comment."

It's interesting that VW didn't fess up until they were forced to.

g:

e =

d y

That's pretty much human nature going back to the Garden of Eden. The next trick is to blame someone else. A TV show from long ago had comedian Flip Wilson on. His line was "The devil made me do it".

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trader_4 wrote in snipped-for-privacy@googlegroups.com:

OK. Just the facts Danno:

Yes, sorry, that's what I was referring to.

Can't remember how many readiness monitors there

By the way, there's an excellent Android app for OBD-II called Torque Pro. The app is $4.95, and a Bluetooth ELM327 OBD-II adapter is less than $10 (I am using this one ). The app does a lot more than just read or clear codes. It will display electronic gauges based on the sensor readings (especially useful for vehicles without temperature gauges or tachoometers). You can set alarms for things like over-temperature. It's also a very accurate speedometer (via the GPS), and it'll measure things like 0-60.

There's no iOS version because Apple forgot to include the necessary Bluetooth profile (SPP) in its devices. There are similar apps for iOS but not nearly as good. This one is one of them but you need to get a Wi-Fi ELM327 dongle, not a Bluetooth one.

I like having a 7" tablet with TorquePro and CoPilot (GPS). I made a holder for the tablet using one of the Panavise mounting brackets . Just be sure the tablet has a GPS chip, since very low-end Android tablets don't have one, nor do Wi-Fi only iPads. You can buy a decent Asus 7" tablet with a GPS for $50 just use a virtual credit card with a $1 limit and a one month expiration date when you sign up with McAffee (required to get the rebate). Intel, which owns McAffee, is trying to promote devices with their processor inside, hence the large rebate.

If they cannot license their cars without a firmware update then they have suffered a loss and should of course be able to sue or otherwise be remunerated. I was thinking about the car owners who live in an area where cars are not smog checked. For example, I live in Island County which is about 30 Miles from Seattle which is in King County. This means I don't have to get my vehicles smog checked whereas King County residents do. I don't know how CA does smog checks but I suspect everyone who lives there has to get one. I can see that I should have thought of that before I posted my comments. I just heard on the news that there are about 450,000 vehicles in the USA that have the dishonest firmware and that the EPA can fine VW $37,500 for each car. I find it amazing that so many people would participate in such a dishonest act, and that it could remain secret for so long. All sorts of folks, from the upper management to the software writers, had to know about and agree to actively participate in the fraud. I can see how some would do so because of greed. And others may have been afraid of losing their jobs. But I would think that many would refuse to commit fraud and that some of them would spill the beans. I guess I'm naive. Eric

Staying on topic, this article says the cheat only worked when there was a DYNO involved!

Here are the contiguous quotes: (begin quote) VW used secret software ? an algorithm that detects when cars are being tested on treadmill-like devices called dynamometers, and stealthily switches the engines to a cleaner mode.

Because *smog tests are almost always done on dynamometers*, VW got away with the scheme for seven years, until the "clean transportation" advocates went to West Virginia University, which tests emissions using equipment that fits in car trunks. (end quote)

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

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?

Oopops. Forgot to include the url:

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

How does this UREA injection work?

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:

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.

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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.

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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.