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Old October 5th 15, 03:33 AM posted to alt.home.repair,rec.autos.tech,sci.electronics.repair
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Default EPA caught VW cheating - how does the car know it's being tested?

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.