Eoin Treacy's view -
But making those rules public does have a downside: It means companies know precisely how to cheat. Here’s how the Jacobs School describes the situation:
During emissions standards tests, cars are placed on a chassis equipped with a dynamometer, which measures the power output of the engine. The vehicle follows a precisely defined speed profile that tries to mimic real driving on an urban route with frequent stops. The conditions of the test are both standardized and public. This essentially makes it possible for manufacturers to intentionally alter the behavior of their vehicles during the test cycle. The code found in Volkswagen vehicles checks for a number of conditions associated with a driving test, such as distance, speed and even the position of the wheel. If the conditions are met, the code directs the onboard computer to activate emissions curbing mechanism when those conditions were met.
But VW didn’t stop there. The researchers who examined Volkswagen’s work pulled 964 separate versions of the Engine Control Unit (ECU)’s code from various makes and models of Volkswagens. In 400 of those cases, the ECU was programmed with defeat devices.
Now, you might be thinking that a single code model couldn’t possibly compare all the variables in play between various test facilities, and that some cars should have shown a fault simply due to random chance. But VW was aware of that possibility and took steps to prevent it. Their defeat device had ten separate profiles to allow it to detect various permutations in test scenarios.
Not all the defeat devices were sophisticated. The Fiat 500X (not manufactured by VW) has a much simpler defeat device. The vehicle’s emission control system runs for 26 minutes and 40 seconds after you first start the car, period. That’s long enough to pass most emission tests, and it doesn’t try to detect if the vehicle is being tested. But VW’s work was extremely sophisticated, it evolved over time, and the company’s claims that this was all instituted by a few rogue engineers are more farcical than ever.
The fact that it has taken this long to figure out just how the diesel defeat mechanisms function highlights the fact that Volkswagen and Bosch have not been entirely forthcoming with investigators. The emerging reality is that defeating emissions testing was a long-term highly orchestrated endeavour that must have required the efforts of teams of engineers and years of work to achieve such impressive results.
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