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The problem is that nobody wrote a specific defeat device. You have to understand, Bosch has one basic (extremely complex) piece of software that goes in pretty
by throwaway79790 9y ago
The problem is that nobody wrote a specific defeat device. You have to understand, Bosch has one basic (extremely complex) piece of software that goes in pretty much every single engine controller. There are some specific functions that are developed at the request of specific customers, but the basics are always the same.
When this general piece of software is set up to control a new engine from an OEM, a multi-year process of calibration starts. The engine starts of failing the emissions tests drastically and over time the calibration engineers tweak tens of thousands of parameters to try to get the emissions to be legally compliant.
This is not an easy process and the calibration engineers have a target, they have to get the vehicle certified for a certain emission class, which in turn is determined by the FTP-75 driving cycle. The news keeps talking about "defeat devices" because the law says that they are not allowed, but reality is much messier. There is nobody sitting there thinking about how to make crazy obfuscated defeat devices, rather there are a bunch of people trying to figure out how to pass the extremely demanding emissions requirement tests without any defeat devices.
- thyselius 9y agoI don't doubt it's this big mess you are describing, but if the engine is actively looking for test/not test and does things like turning off particle filtering after 30 minutes of driving because it knows any test will be over, it seems to me the intention is in fact to lie about the real emissions.
- luca_ing 9y agoThe thing is that detecting test situations is good, certainly useful, perhaps necessary. E.g. detecting you are on a test stand, you might * deactivate plausibility checks which would normally limit engine power * deactivate air bags and other inherently dangerous systems * ensure correct system behaviour even if sensors give conflicting information * suppress error logs for certain failed plausibility checks The only illegal thing is switching to a "massaged" parameter map under these conditions. And presumably a single person controlled this switch.
- gruturo 9y agoThis. A thousand times this. They didn't write a defeat device to "fake" emissions, they wrote legitimate code aiming to make the car truly compliant with the requirements. Then someone made this code not the default and, except when the car is under testing, loaded an alternate mapping of some key parameters which is more tuned for performance and mileage, at the expense of emissions. This is the criminal part, not the first.
- ant6n 9y agoBut somebody had to write code that recognizes that an emissions test is being performed, no? I mean that sounds like it would be more involved than just loading some different set of parameters.