Somewhere, this software sits in a source code repository. Someone planned it, wrote it, reviewed it and approved it. Where are these people, and why are they not speaking up? Why have there not been any whistleblowing on this, it's huge?!
What I have seen missing from most reports is that VW does not make the ECUs. Consumer reports has reported[1] that Bosch was the company that produced these ECU. So Bosch should have the repository and should have a request from VW to implement this particular code. I wonder if Bosch will be forced to throw VW under the bus.
If this is provided by a third-parties, there is a requirement written somewhere for the supplier to have two different modes of operation, one for test and one for road. This is likely redacted to be innocent sounding, but there is definitely a DOORS history that would give the date and the name of the people who have written the requirements.
However there might be some good reason to have a test mode, for engineering tests, for example. The culprit would be the one who have decided to ship it and activate in production.
This is definitely a question I have especially since in my experience sometimes you had trade-offs due to other restrictions so every functional item needed to have value and new functionality may require removing/changing/disabling other functionality.
It's common for a larger OEM like VW to write large parts of the application software themselves and send it back to the Tier-1 ECU supplier only as object files. (The industry is competitive, worried about IP protection, and anything clever in the powertrain ECU application software could easily provide a competitive advantage).
Bosch would have ultimately integrated it and built the final ECU software, but I very much doubt they ever saw any source code from VW.
One of the previous articles had a comment from a Bosch representative. It said roughly "yes we supply the ECU, and no we don't perform integration or fine-tuning". Which makes sense, in the same sense that SSD vendors typically source their controllers from a supplier and then adapt the firmware to match their hardware layout/performance objectives.
The maker of the ECU is not necessarily the one who does all (or even most) of the software development for that ECU.
AFAIK the code running on the car model in question is largely from IAV, and some is probably code developed by VW.
Suffice it to say that every auto maker who has to pass Euro emission tests is doing this to one degree or another, and has been for years. Mechanics know it, as do the regulators who resist attempts to reform the emissions legislation.
All of which is to say that this is bigger news than it seems, mostly because the US EPA is actually following up on this.
