Originally posted by Carsten
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The problem is with the regulations that were developed in the era of carburettors and simple ignition control systems. Even the PC was not around when the regulations that everything is based on was first developed. These days, everything changes, and there would not be a single car maker in the world who would have engine mapping that remains unchanged. If any sensor detects a change in its inputs, the mapping of the engine will change. This is not something unique to VW.
Where it does become a problem for VW is if specific inputs intentionally disabled emission control systems with full knowledge that such disabling would result in an increase in emissions that are of the order reported. This cannot be established because no one knows exactly what has happened.
When you look at the definition of a defeat device, basically ANY system that changes mapping from that used in the test would qualify, and this means that there is not a single manufacturer that would be able to duck that one. Even if they claim that their mapping does not change, the mapping would be designed to produce a favourable result in the test, and never mind elsewhere. Engine management systems are dynamic and it would be close on impossible to cover every possible combination of inputs from the sensors.
But given that the vehicles in question have no DEF injection and so far no one is suggesting that there were bypass pipes for the DPF and catalytic converter, the only thing I can see is varying the fuel injection map, the amount of EGR, and when the wastegate opened. Even with the wastegate, I would expect it to connect back to the exhaust downstream of the turbo and before the first of the emission control devices.
We wait for VW to come clean.
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