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

On 05/10/15 13:33, sms wrote:
On 10/4/2015 2:39 PM, Klaatu wrote:
According to NBC, the emission controls were altered when only the front
wheels were turning, as on a dynometer.
I don't know about diesels, but newer gasoline powered cars in
California don't use the dyno anymore. The levels are all read from the
sensors via the OBD-II port, at least in California.

It's trivial to detect that the car is not being driven.
No steering wheel motion, no compass variation, no accelerometer (if
fitted), no... you name it, I'm sure there's a long list of candidates.

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

On 10/4/2015 9:04 PM, Clifford Heath wrote:
On 05/10/15 13:33, sms wrote:
On 10/4/2015 2:39 PM, Klaatu wrote:
According to NBC, the emission controls were altered when only the front
wheels were turning, as on a dynometer.
I don't know about diesels, but newer gasoline powered cars in
California don't use the dyno anymore. The levels are all read from the
sensors via the OBD-II port, at least in California.

It's trivial to detect that the car is not being driven.
No steering wheel motion, no compass variation, no accelerometer (if
fitted), no... you name it, I'm sure there's a long list of candidates.
YOu're overthinking it. It's about driveability
If the rear wheels ain't turning, you should turn on the emission
controls. When the car is stopped in traffic, might as well make it
clean. Performance isn't an issue when stopped.
I'd have taken it a step further and made it clean whenever driveability
isn't compromised...like when not accelerating at a rate faster than
you could do with the emission controls functioning.
Probably would never have been detected.

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

On Sunday, October 4, 2015 at 10:33:33 PM UTC-4, sms wrote:
On 10/4/2015 2:39 PM, Klaatu wrote:
"Ewald Böhm" wrote in message
...
Apparently Volkswagen/Audi cheated on the USA emissions tests since
2009 to 2015 by turning off the EGR to lower nitrogen oxide emissions
ONLY when the car was being tested for emissions.

REFERENCES:
http://blog.ucsusa.org/volkswagen-ca...cle-recall-887
http://www.engineering.com/AdvancedM...EPA-Tests.aspx

http://hothardware.com/news/vw-inten...-482k-vehicles

etc.

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


According to NBC, the emission controls were altered when only the front
wheels were turning, as on a dynometer.

I don't know about diesels, but newer gasoline powered cars in
California don't use the dyno anymore. The levels are all read from the
sensors via the OBD-II port, at least in California.

I'm not sure they even read levels. They do check to make sure the
emission ready monitors have been set, which indicates that if the
computer has been cleared, then the car has been driven long enough
to reset them. Other than that, they are probably relying on the
computer not having any emissions failure codes set. The cars don't
have the instrumentation to measure all or maybe even any of the
actual emission components directly. Whatever they measure, it's
obviously even easier to cheat when only the OBD is used. The computer
just says everything is OK all the time.

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

On Monday, October 5, 2015 at 3:06:21 AM UTC-4, mike wrote:
On 10/4/2015 9:04 PM, Clifford Heath wrote:
On 05/10/15 13:33, sms wrote:
On 10/4/2015 2:39 PM, Klaatu wrote:
According to NBC, the emission controls were altered when only the front
wheels were turning, as on a dynometer.
I don't know about diesels, but newer gasoline powered cars in
California don't use the dyno anymore. The levels are all read from the
sensors via the OBD-II port, at least in California.

It's trivial to detect that the car is not being driven.
No steering wheel motion, no compass variation, no accelerometer (if
fitted), no... you name it, I'm sure there's a long list of candidates.
YOu're overthinking it. It's about driveability
If the rear wheels ain't turning, you should turn on the emission
controls. When the car is stopped in traffic, might as well make it
clean. Performance isn't an issue when stopped.
I'd have taken it a step further and made it clean whenever driveability
isn't compromised...like when not accelerating at a rate faster than
you could do with the emission controls functioning.
Probably would never have been detected.

Actually, we're not sure what the real issues were. There is speculation
that it's MPG and performance, which if true would make what you say true.
It's also possible that some emission components are adversely effected,
don't last as long, will fail if used continuously, etc. The last thing
I saw, VW is saying that it was done because they could not meet both
emissions and cost constraints. Which might play into the scenario that
if the emissions controls are on continuously, or used enough, something
bad happens.