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

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On Sat, 19 Sep 2015 05:30:45 -0400, Steve W. wrote:

I just had mine tested, in California, and they used a dyno. No OBD hookup whatsoever.
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On 9/19/2015 10:51 PM, Ewald Böhm wrote:

How did they check for pending codes if they did not use a code scanner? You can't pass with more than two pending codes (one on some years).
That shop would be shut down by the state if it was found that they were passing cars without checking for pending codes.
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They look for the light on the dashboard that indicates codes have been logged.
In some places they always use the scanner to make sure, for instance, that the ECU wasn't reset immdiately before taking the car in for inspection. In some places they do not. --scott
--
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On 20 Sep 2015 12:12:31 -0400, snipped-for-privacy@panix.com (Scott Dorsey) wrote:

Except "pending"codes don't turn on the CEL, and the CEL does not indicate if monitors have been "set"

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On Sun, 20 Sep 2015 12:12:31 -0400, Scott Dorsey wrote:

That.
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On 9/20/2015 9:12 AM, Scott Dorsey wrote:

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.
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wrote:

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.
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On Sunday, September 20, 2015 at 7:58:13 PM UTC-4, snipped-for-privacy@snyder.on.ca wrote:

I was thinking that too, ie that it's the monitors, not pending codes. Pending codes would be fault conditions that have been detected but haven't occurred enough to put activate the check engine light. The emissions monitors are flags that are set on the critical emission related systems. If you clear the computer, those flags get cleared. When the car is driven, they get set again over time as the system accumulates info that shows they are working. There are about 10, I think. Most get set within minutes. The fuel evap system takes the longest, probably takes multiple drive cycles to set.
Here in NJ with older cars you can pass inspection with two not set. Newer cars, no more than one can be not set. Maybe some states are concerned with actual pending codes, but I doubt it, because they don't necessarily mean anything is wrong and would just create a lot of drama for nothing.
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On Mon, 21 Sep 2015 05:20:13 -0700, trader_4 wrote:

In California, they can refuse the test if the readiness monitors aren't fully set, even if you'd still pass otherwise.
They get dinged on demerits for every readiness monitor not set, even if it's within the limits of the law.
Such is bureaucracy.
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On 9/20/2015 4:57 PM, snipped-for-privacy@snyder.on.ca wrote:

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 <http://www.dx.com/p/super-mini-elm327-bluetooth-odb2-v1-5-car-diagnostic-interface-tool-blue-142679 ). 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. <https://play.google.com/store/apps/details?id=org.prowl.torque&hl=en
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 <https://itunes.apple.com/us/app/engine-link-obd-ii-vehicle/id591557194?mt=8 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 <http://www.panavise.com/index.html?pageID=1&id10&startat=1&--woSECTIONSdatarq0&--SECTIONSword=ww . 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 <http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo 61735> 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.
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On Sun, 20 Sep 2015 15:49:16 -0700, sms wrote:

It's usually documented as the FTP.
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On 9/20/2015 3:49 PM, sms wrote:
<snip>
I had a smog check this morning on a 2007 Camry. The shop had a new machine for newer vehicles. Since September 2013, 2000 and newer vehicles no longer get tested on the dynamometer and no longer get a probe shoved up their tailpipe. The whole test is done via the OBD-II port (as well as a visual inspection).
For diesel vehicles you can see the details here: <http://www.smogtips.com/diesel-smog-test.cfm
So clearly VW was not just looking at wheel rotation, they probably turned on the emission controls whenever they detected something reading the sensors. I wonder if an ELM327 transceiver or a Progressive "Snapshot" would have any effect.
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Here's an interesting point. It seems CA has portable roadside emissions checkpoints that measure the emissions as you drive. I wonder why they haven't seen a major problem with VW vehicles as they pass these checkpoints?
Maybe it is a minimum difference between a properly working system and a VW in the fuel economy mode? Like someone else said - is the nominal emission near zero and 10 to 40 times worse is still an extremely small amount of NOx.
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On Monday, September 28, 2015 at 9:19:10 PM UTC-4, sms wrote:

AFAIK, when they use the OBD method, all they are looking at is if the emission monitors are set and that there are no emission related engine codes set. None of that requires the car's emission system to be actually working, just that the OBD software in the car, which VW wrote, reports the above. The car could be spewing out anything and pass the test.
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wrote:

In ontario the testers are directly connected to a central computer and it is virtually impossible to go from stem 1 to step 3 without completing step 2 first.
A number of years back, some crooks were running a "good" vehicle through the test 5 or 6 times, entering the Vin for one that would not pass. They made changes to the system that prevented that pretty quick.
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On 9/20/2015 12:32 PM, snipped-for-privacy@snyder.on.ca wrote:

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.
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Ewald Böhm wrote:

http://obdclearinghouse.com/index.php
--
Steve W.

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On Sat, 19 Sep 2015 04:45:38 +0000 (UTC), Ewald Böhm

Don't know how other jurisdictions do it, but in Ontario the old "drive clean" test was a "rolling road" sniffer test at two speeds, with the car connected to the computer via the diagnostic port, but not accessing discrete codes.
The new system does away with both the "rolling road" and the sniffer, meaning it can only "guess" or "deduce" if the NOX is within range - it cannot tell if the reduction catalyst is working because only the oxidizing catalyst is monitored by the secondary O2 sensor.
It is POSSIBLE that VW implements the "over-ride" whenever a certain sequence of events is performed that are substantially the same as the initialization procedure for running the test (There is a perscribed sequence of events that MUST be performed to get a valid test result) (like 20 many seconds at a particular RPM, followed by another given period of time at another RPM) which, if performed during the normal process of driving would also put the system in "bypass" for the anticipated duration of the test.
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In alt.home.repair, on Sat, 19 Sep 2015 04:45:38 +0000 (UTC), Ewald Böhm

Maryland used OBD on cars new enough. That includes my 2000 car, but I don't think included my 1995 car.
(For the 1995 it used the dynamometer and tailpipe stick) I think when I turn 70, if I don't drive too much, I won't have to be tested. Or my car.
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wrote:

Officially, all cars 1996 and newer must be OBD2 compliant, but most jurisdictions using OBD2 for E-Testing only start at 1997 models because some 1996 models were not fully compliant. Only a very few 1995 vehicles had OBD2 capability as 1995 was "pre-standard"
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