"How was it done?" or "How could it happen?" 

How was it done has many answers that are technically easy. I don't know the specifics about VW's software but if the lab test is performed on a drive wheel rollers then it is easy for the ABS software to detect that the drive wheels are turning, but the others wheels are not. Then the ABS code could tell the emissions code to run with clean parameters instead of best power/economy parameters. The ways to accomplish the cheat are limited only by imagination, but they are still cheats. 

The flexibility of computers, software and sensors makes the technical part easy. The bigger question is how could a company could cheat against the environment and its customers.  I hope VW makes this right and the episode is a wake up call for the industry.

Sent from my iPhone

> On Sep 25, 2015, at 10:14 AM, Karl Ploessl <karl.ploessl@GMAIL.COM> wrote:
> 
> so we know that VW "cheated". But how was it done?
> 
> CEO says to his underling: go and get the the diesel engine certified.
> Underling goes to his/her underling and tells them get it done. And so on.
> Diesel engineer knows that it can't be done and orders the programmers to
> put in cheat code. So there must be lots of people involved who "knew", at
> least programmers, engineer? Everybody is quiet, doesn't go home and tells
> SO about the work? SO doesn't chat with neighbors....
> Difficult to imagine that everybody kept a quiet lip... but has to be like
> that?
> 
> What other scenarios are possible?
> 
> On Fri, Sep 25, 2015 at 12:13 PM, Richard Smith <richard_smith@gnwc.ca>
> wrote:
> 
>> Small to medium sized enterprises.
>> --
>> On Sep 25, 2015, at 7:16 AM, Sudhir Desai <sudhir.desai@GMAIL.COM<mailto:
>> sudhir.desai@GMAIL.COM>> wrote:
>> 
>> SME being ? (sorry, the only SME I know is a Subject Matter Expert)
>>