Slashdot Mirror
Volkswagen Diesel Scandal Logistics Imply Sizable Conspiracy
Guinnessy writes with an interesting analysis of the Volkswagen software cheating scandal: Physics Today's Charles Day takes a look at how diesel engines work, and why it's clear it's not just a lone software engineer who came up with the cheat. "...[S]oftware is impotent without hardware. To recognize when a car was being tested and not driven, the defeat device required data from a range of sensors -- sensors that a noncheating car might not need.... Whereas it's conceivable that a single software engineer, directed by a single manager, could have secretly written and uploaded the code that ran the defeat device, installing its associated hardware would require a larger and more diverse team of conspirators," he says.
I've worked as a partner for some car companies in both the US and the EU, and I know for a fact that the firmware that goes into their control systems is very tightly controlled, requiring sign-offs from senior execs for design and feature changes. There's no way code this critical could have simply been dropped in by some R&D leads. No. Way.
If you put any thought into this at all, you realize it is a massive conspiracy. Other automakers add expensive, space consuming devices to eliminate NO pollution. These is no way a single programmer could have made a change and all the engineers would go "Look, we don't need all the extra hardware, it passes the test!" Lots of people would notice immediately during the design phase.
Might not need vs does not have is a stretch. I would think all the information to determine if it's being tested or not would just be accessible by some main controller engine API. It seems the sensors needed to tell if it's being tested or not were really basic stuff like finding out if it's moving or not vs how fast it was being driven which could be required by the hand breaking system or a sensor to tell if the steering wheel is moving or not which could be required to turn headlights in the direction the steering wheel is turned etc. Excluding these build-in hardware sensors from a car that does not have extra options payed for by the owner might not be cost-effective when mass producing and reusing much of the same parts / wiring. Not paying for one of those options does not mean the sensors are not in place.
Some of the extra options you select when buying a car are software driven things with an extra switch in the console to turn it on/off. Not paying for it does not necessarily mean none of the hardware is installed or that none of the signals are available in the API.
The linked article makes the point that the sensors and hardware would not be necessary. I think the writer seriously underestimates to what extent a modern car with protection systems will try to juggle different constraints. Things like non-driving wheel rotation (defeated by being on a lab stand) are needed for breaking systems and possibly to some extent to moderate throttle control for stability. Wheel movement patterns are also needed and useful, even if you don't actually have electric power steering.
Regulating the exhaust gas recirculation somehow also makes sense. You might go totally on and off, but you would certainly want to keep it at a sensible level. You want good acceleration and full combustion of fuel while still not emitting to much nitrous oxides. It makes total sense to me that you might want to design your control system to try to judge not only the current emission levels, but also the overall driving pattern (steady straight ahead, repeated stop and go, etc) with some kind of state machine to try to find the best EGR regulation regime. This requires sensors and ways to regulate the feature.
My most innocent guess about how something such as this might have happened was an intent to find a good regime that would give nice bursty performance, while keeping nitrous oxides low overall. Progressively, the control regime was pushed until it ended up in the corner where the case of EGR being properly activated under real-world conditions basically does not happen. Some parts of it might even in the end be a bug between the intended state transitions and the actual ones. Like all bugs that give performance that seem too good to be true on the metrics you really care about (fuel consumption and enjoyable driving), no-one investigated.
Do I think it happened this way? It's hard to say. Probably not. But, in one way, it's even more frightening than an evil conspiracy. It's easy to say "I wouldn't take part in a conspiracy by my employer". It's harder to say "I would never be pressed to write code with goals that could not be fulfilled, eventually find a hack that seemed to work, and maybe ignore investigating why it worked so well"...
At what point does a group of people, perhaps thinking they're working to create something good, but that actually results in something that maybe isn't so good, become a "conspiracy"?
Let's look to open source efforts like GNOME 3 and Firefox 4 (and later versions). Here we have well-established software products, with many users, and extensive communities built around them. While they'll take outside contributions, stewardship of such projects is quite tightly controlled. Yet at some point, very bad decisions start being made by the developers of the products, and not necessarily in bad faith. There comes a point where some influential members of the community think it's important to target "average users" or "mobile users" or perhaps to compete with a similar product from another vendor by imitating it.
But by doing so, they end up completely trashing their own products. A desktop environment like GNOME 3 becomes almost completely unusable on the desktop by power users, who make up the bulk of its community. A browser like Firefox throws away an intuitive and usable UI for one that's nonsensical in most ways, while long-standing performance problems, resource usage excesses and bugs remain unfixed.
Yes, many people can be and are involved in such debacles. But do we know that they were all acting maliciously? Do we even know that they actually knew what they were doing? Somebody pushing for Firefox's awful Australis UI, for example, may have thought he was helping design a good, novel UI. But rational outsiders and Firefox users thought very differently, clearly. That's why Firefox is now at only about 7% to 8% of the browser market, when it used to be above 30%.
We can't deny that GNOME 3, and Firefox version 4 and later, have been project-level failures involving many people. But despite the negative and unwanted outcomes, it's difficult to say with certainty that there was any sort of "conspiracy" involved. It could very well be people working together in good faith, who unfortunately only end up creating a very awful outcome.
Modern cars use a system to stabilise the car in the event that one or more wheels starts to lose adhesion - commonly called things like ESP/DSP/ESC
The car wants to know when it's on a dyno or other testing device where only one set of wheels move, and the others do not - if this were NOT the case, it would assume that the rear wheels have lost adhesion with the road, and will serious interfere with the power provided to the front wheels.
So "the defeat device required data from a range of sensors -- sensors that a noncheating car might not need" is totally and utterly rubbish, it likely needs a single line of code like this:
> if(EngineMode.Test){ ... do something to improve emissions ... }
Furthermore, many cars may already have a "very low emissions" mode or similar - there may not be a "special" mode specifically for EPA tests which a different profile for timing, fuel injection etc. - the cars computer essentially changes the "configuration" of the engine on the fly, based on driving conditions, driver input, gear, fuel quality, engine feedback etc - and it does all this during NORMAL operation.
If a "high efficiency / low emissions mode" already existed, then the code could be further reduced to
> if (EngineMode.Test ){ Engine.PerformanceProfile = LowEmissionsProfile }
Of course, it's unlikely that there would be a high level language available to engineers to make it quite so readable as above - but hopefully the code illustrates the point.
FWIW I strongly suspect that the "low emission profile" in place here in VW *IS* a "special" doctored one to fool emissions tests, but the detection of actually being in a test? Probably already existed.
Has anyone fully tested all other cars?
Not that it's an excuse, but if everyone's doing it, it's a different story.
Hint: many VW owners already mod their cars illegally, so allow tailgating Priuses to listen to the song of their people.
I think the explanation as to why diesel engines create more nitrogen oxides and how the EGR works was simple and on point, but the conclusion not so much. I drive a diesel myself, but it is a 2006 model, it doesn't have adblue injection, my exhaust system only has a catalytic converter and a particle filter (and an EGR, of course). Even though it is an old model, like most cars since then it has more than enough sensors to do what VW did: individual wheel speeds for the ABS, steering wheel angle for the ESC, multiple sunshine sensors, front and rear suspension angles for the headlight height control, multiple temperature and pressures sensors on both the intake and exhaust, multiple flow rate sensors, mass air flow sensors, multiple sensors in the cooling system etc.
That's why I find the article a bit thin on new information, I'm certain the embedded engineers at Bosch/Delphi/Siemens/etc. could have done that with far less information that a more modern car has.
Did they all knew about it? Probably. Did they made hardware efforts to cheat? I don't believe it yet, that's the point of cheating, "passing" the test without having to add new hardware, there is plenty of data that can tell you if the car is really moving or in a test chamber.
The sensors required to detect "test mode" and software driven EGR control hardware are already part of any modern car so there was no decision to "add" them to accomplish this cheat. But there had to be a strategic decision to not to add SNCR, and that is a decision that could only be made at a very high level.
Yes, but that was not a conspiracy. It was very clear in the specs and even highlighted as an advantage. The question is "who knew and approved, at what point, that this design would not work out in practice". Even the idea that smart design of the control regime would make it possible to achieve low emissions without SNCR is not, in itself, equivalent to fraud. It's only when this design becomes all about "detecting test conditions" things get really, really bad.
Anyone who actually works in the auto industry is pretty much certain this wasn't a lone-wolf operation. I know because I've been in the industry myself for a good chunk of my career including right now. This is very much the water cooler talk right now and nobody believes it was just one or two guys. I run a company that makes wiring harnesses and many of our products go into automobiles made by the Big 3. There are WAY too many people and groups involved in the engineering, design and testing and manufacture of these cars for this to be pulled off entirely in secret. While it would not have been known across the company it would have had to have been signed off on by more than a few including engineering, management and probably testing as well.
This was not done by accident. It was not done by some poor engineer asked to do the cheat on pain of losing his job. This was an intentional and premeditated fraud and it isn't the first time something like this has happened. About 15 years ago a bunch of truck manufacturers including Volvo and Caterpillar were caught doing something similar. Probably won't be the last time we see it either given the amount of money at stake. While I'm sure VW is probably going to try to throw some low level people under the figurative bus, I'd be shocked if this didn't go pretty far up the food chain. Maybe not all the way to the top but probably up to the heads of engineering and R&D at the least. I can't imagine how the engine designers and their management team wouldn't know. This stuff isn't magic and questions would be asked for which there is no satisfactory answer via software.
Many sports cars have at least two performance settings...Mustangs with their Black key and Red keys for instance. How stupid would that be if it didn't change the performance of the engine? And when you do that for more power, you are undoubtedly going to get worse mileage and emissions.
So what does the EPA do? Test the cars in "normal" mode and assume that no one will really ever use the "sport" mode? Reality says almost everyone will be in sport mode all of the time.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
To recognize when a car was being tested and not driven, the defeat device required data from a range of sensors—sensors that a noncheating car might not need.
At what point does a group of people, perhaps thinking they're working to create something good, but that actually results in something that maybe isn't so good, become a "conspiracy"?
The moment it becomes obvious that what they are attempting is impossible and they start looking for illegal ways to circumvent a test. At that precise point they should have stopped and done something else.
There is no real grey area here where people weren't fully aware of what they were doing and at no time were they under any illusion about the legality. The people who implemented this are professional engineers who knew(or should have known) what the rules were and decided to go ahead anyway. This isn't a piece of consumer software where there are no federal laws involved. This wasn't a piece of software where what seemed like a good idea ultimately didn't work. No, they intentionally and with premeditation committed this fraud. Stop it with trying to excuse what they did.
this sort of cheating is- I assume all the car makers are going to get looked at if not by government agencies, by independent interests. We'll see just how far this string of potatoes goes when the pulling starts.
Citations needed...
Son, have you ever worked on any sort of a project that involved more than just yourself and a bag of Cheetos?
Individual participants on any significant project aren't "fully aware of what they were doing" all the time. That's what happens when the project is big, many highly specialized people are involved, and few people see the big picture.
That's exactly what the original point was: a lot of individuals making small changes over a long period of time can collectively create something that's generally harmful, even when each individual was working totally in good faith.
One Firefox developer removes the menu bar, thinking it will simplify the UI. Another adds in the hamburger menu, thinking it's what users want, since Chrome uses one and many Firefox users are flocking to Chrome. One more removes the status bar, since it will show 20 more vertical pixels of the web page.
All of those Firefox developers may have been making small, legitimate changes, and working in good faith. But put their work together, and they unknowingly and unintentionally destroyed what was once a very usable user interface.
We hear a lot of people like you parroting on about "conspiracies", yet we see very little direct evidence from you to back up what you're saying. Yes, a lot of people are involved in big projects. Yes, sometimes bad things result from such projects. But before you can cry "conspiracy", you actually have to have some small shred of evidence to show that there actually was a conspiracy!
The mantra of optimization is you get what you optimize for. It's amazing how that seemingly innocuous phrase is something every person doing optimization has at some point been bitten in the ass by at least twice. Once when you do something stupid as you are learning and once later when the optimization produces some completely perplexing result leaving you in awe of the power of that mantra.
There was likely no conspiracy precisely because of the difficulty of maintaining the conspiracy at this scale. A much simpler explanation is that they had the system train itself. There's no reason to leave out certain features in the input vector so all the sensors go in. The car learns that when there's no frequent steering input and the cost function is dominated by emissions then you minimize the emissions. And later on the test track, where there is no emissions term in the cost function, the car learns to anticipate accelerations when there is steering input, so the cost function optimizes for performance and fuel economy not emissions. and so on.
One can see how this could happen so easily. And even if one group thought about it they didn't control the whole cost function and were exploring one part of it. Component manufacturers might notice this too but assume it's fixed in the full system. indeed one report said that there was some internal review of some odd issues.
But if you aren't expecting this and you are relying on the model training to integrate many different team testing one can see how this could accumulate.
It's also easy to see how this could even be seen and not noticed. For example, shutting down emission controls and air conditioning and other things is completely the norm in perfromance tuning. When you stomp on your accelerator the clutch in your Air conditioner disengages to give more power. THe exhaust gas recrculator shuts off. You want those things to happen, just as you want the turbo to kick in before you need it and to kick out when it won't be needed. Thus cars that anticipate these changes rather than wait for then feel much more responsive yet can get much better emissions and fuel milage.
But one can see that these traits could accidentally "cheat" when ever two different optimization features come into conflict.
Some drink at the fountain of knowledge. Others just gargle.
I think that you missed the point of the previous post. It could be that many people involved thought that they were adding a performance function.
I did not miss the point. The point was wrong. They did not think they were adding a performance function. That's not how it this stuff gets developed. They would have known if this idea worked or not before it left R&D.
Granted, at some point it clearly crossed the line.
And that is where they should have stopped. No equivocation is necessary. The moment they realized it was illegal/impossible they should have stopped. It was reasonable to try to come up with a clever way to avoid the cost of adding a urea injection system but the would have known if this was feasible before the idea left the R&D lab. Once it got to the production engineers, there is no possible way they didn't know that what they were doing.
The auto companies repeatedly test the cars on their test bench. They use specially instrumented engines that collect so much of data on those test cars. Knowing which data was collected on the test harness and which were real road data is a legitimate data for debugging and fine tuning. The amount of data collected (actual valve position, commanded valve position, sensed crank angle, actual crank angle, time fuel injector open, time fuel injector done, blah blah ...) would so copious they might turn off certain data collections under certain circum stances.
They might have started with a special manual switch on the dash to turn on "test bench" mode. They forget to turn it on a few times, invalidating lots of collected data because "on test bench" field was wrong. Some clever guy suggest automating it. All these would be very legitimate and most engineers on the team would be working on good faith that it is not a cheat device.
What I am trying to say is "auto detection of test bench run" has a legitimate purpose. They also have so many use profiles. CA air standards profile, Euro air standards profile, China air standards profile, India air standards profile etc. All these use cases are also quite legitimate. All the engineers working on all these projects would be doing work without compromising their integrity or ethics.
Eventually someone high up had a clever idea to load China/India urea use profile when the car is not on test bench. This work does not involve company wide collusion. It would require very few engineers on the coding side and a few top level managers. They would know what they are doing is implementing a cheat device. They might have even done it as a stop-gap measure intending to correct in a few weeks or few months.
Some scenario along the lines of ... "Heinz, the air-quality team needs a few more weeks, they are behind, we are going to miss the deadline. But they are close, just a few more weeks. For now let us load India profile when not on test bench, once the air-quality team finishes the project we can quietly restore the setting. Or we have to delay the ship date by a few weeks". "Erwin, are you sure they would be done in six weeks". "Definite, absolutely". "OK I will talk to Walter and Karl. Keep Adolf and Joseph out of the loop. Keep it under your hat, and make sure there is no paper trail".
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
The author did a good job of explaining how EGR reduces efficiency. But it's not clear to me that additional hardware would have been required to make the cheat work.
Because emissions tests have (up to now) been done on a treadmill, it was necessary for many cars to have a "test mode" already, to prevent problems with electronic stability control systems due to two wheels spinning on the treadmill, while two wheels remained stationary. So test detection would have already been present, for legitimate reasons. Likewise, the EGR system would have needed continuous control for normal operation of the engine.
So while I agree with the premise that many people had to have been involved in engineering the cheat, I'm not sure that additional hardware would have been required.
Only sensors required to determine which wheels are moving are wheel speed. Any ABS equipped car needs those for at least 3, and usually 4 wheels so that ABS works properly. Does not require conspiracy to put in extra hardware.
If he'd bothered to speculate, he probably would have realized he was wrong. Day appears to be good at summarizing physics, but cars are more complicated than they appear at first glance.
Whereas it's conceivable that a single software engineer, directed by a single manager, could have secretly written and uploaded the code that ran the defeat device
Of course is conceivable, but does anybody actually believe that ? You would need to be quite ingenuous to believe that... this is not an obscure open source project with almost no reviews, you cannot "slip" a patch without anyone noticing... moreover, you cannot keep that code for more than 6 years in the revision control system without anyone noticing.
This is not a conspiracy, this is just a company caught red handed.
Anyway, if you need any proof that this behaviour was indeed intended by the company, just have a look at this article: Bosch reportedly warned Volkswagen about illegal emissions software in 2007.
TFA references a youtube video ( https://www.youtube.com/watch?... ) which references "my 2002 Volkswagen Jetta TDI." the VW diesel "cheats" only started in 2008.
WIthout facts TFA is rubbish.
Anti-lock brakes, computer controlled transmission shifting, variable assist power steering, fly-by-wire throttle and closed loop engine management all require sensors. Taken together, those sensors exceed what's needed to explain VW's cars ability to distinguish between active driving and a steady state test.
The issue is not that there was hardware included that enabled the software cheat, the issue is that the software cheat enabled not installing hardware (a SCR system).
While the cheat could have been implemented by a small group, the decision to not install an SCR system was an executive level decision.
Despite my claim that it may have been an accident of optimization I do have an alternative theory. I imagine that the VW designers got up against a deadline. Perhaps the above referenced possibility of an optimization error had actually led them down the wrong track to a point were it was too late, things were tooled, people trained etc... Have to forge ahead. So plan B becomes, well let's fake it to buy some time to build the right engine. they already know how to fake it since they had managed to fool themsleves. So they go big, boast of clean deisel and then try to make the engine achieves that. When they find they can't they have a problem. If they put in the new engine it would be clearly worse than the old engine and that would bring scrutiny. And for some reason they figure, well no one noticed to maybe we can just keep pushing this out longer till the next round of emission laws gives us cover for a change of engine.
Some drink at the fountain of knowledge. Others just gargle.
Day doesn't even bother to speculate. His entire case is:
To recognize when a car was being tested and not driven, the defeat device required data from a range of sensors—sensors that a noncheating car might not need.
ABS/traction/stability system is enough to realize that the car isn't really moving, and that one set of wheels aren't rolling. Under normal driving, whacky signals in such a system might be cause to down-tune engine performance a bit, given that braking might not be optimal... A normal precautionary function that kicks in at testing too... Obvious cheat! Not speculating at what was known, what should have been known/realized, what was 'actively ' ignored, etc.
this is not an obscure open source project with almost no reviews, you cannot "slip" a patch without anyone noticing..
So, this is the automotive equivalent of systemd?
Have gnu, will travel.
Keep in mind that both German state governments and Volkswagen workers have substantial representation on the board, and a lot of input and responsibility for Volkswagen's business decisions. They either knew, or ought to have known, about the emissions fraud.
The fraud should also have been obvious from the fact that these cars are tested in Germany and other countries as well, and that other manufacturers were unable to match VW's emissions even though VW didn't have any known technology to reduce emissions.
Volkswagen, like all big German companies, has a substantial participation of workers in management decisions. Volkswagen employees realized that they would hurt their company and their own financial interests and the interests of their friends and coworkers if they caused their US sales to tank by revealing the fraud.
You do realize that Volkswagen is a German company and run rather differently from US companies?
While VW has cheated the author simply get things wrong.
1. The "defeat device" is in software only. There is no magic extra hardware to make things like this happen. No extra sensors were required.
2. The EGR valve is not a bad thing. Yes, they do cause problems from time to time, especially in diesels. But it is a necessary evil in ALL modern engines. Gasoline engines have EGR valves too. Without an EGR valve, efficiency and emission control would be nigh on impossible.
3. Removing the EGR valve is not a good idea for emission control. Your car will break every emission control standard from atleast 15 years back once you remove it.
4. A fix simply constitutes of software changes. There is no need for extra hardware.
I could go on... But the main thing is that the author is drawing attention by shoving sticks into a fire which he does not understand.
Who wrote the software and who told him to write the software?
Since the emissions test is done on a dynomometer, constant-speed portions of the test will have much less speed variation than normal driving. The lack of small accelerations could fool an "honest" emissions control algorithm to spend an abnormal amount of time in an ultra-low emissions mode. Therefore, making the algorithm "completely honest" would require that it know when it was under test and select operating modes which more closely emulate real-world driving conditions.
The above argument ignores the fact that it is perfectly legal to "design to the test". Since the beginning of the US EPA tests, cars where designed to have their fuel consumption minima at exactly the condition used in the EPA test, without explicitly sensing that they were under test. (In the early days, when the national speed limit was 55 mph, the highway mileage test was done at a constant 49 mph.)
My point is that, as both emissions control algorithms and the associated regulatory tests become more sophisticated, it may be necessary for the engine to cooperate with the test equipment. In that case, prudent regulators should institute some degree of code inspection to ensure that the cooperation is not malicious.
If the OP or Charles Day had any clue whatsoever about Volkswagen products, they'd know that all these sensors are available on all cars from pretty much all platforms from 2000 forward, that they all communicate on the CAN-bus, and that they all need input from those sensors for a variety of reasons having nothing to do with engine performance, period. (Steering angle - ABS or steerable headlights; wheel speed sensor - circumferential flat detection, ABS, etc)
They may have known, but what was the alternative? Get fired, and in a manner that ensures they will never work in their field again?
The alternative is that you don't commit a crime. Why is that so hard to understand? This was FRAUD, plain and simple. If my boss comes to me and asks me to commit a crime so the company will make more money my answer is to gather my personal effects and seek employment elsewhere.
We are not talking about engineers who lacked options. The auto industry isn't one where they can get blackballed from every working again. These are well paid, educated people who knew (or should have known) what they were doing and decided to commit a crime.
Or go to the regulator and media, bring down the responsible parties, and get sued so hard their grandchildren will be paying the lawyer bills?
You can do that OR you can just leave. Either option is better than committing a crime.
The engineers aren't in charge.
Doesn't matter. The engineers are responsible for their own actions. They chose to commit a crime when asked and they are just as responsible as anyone else involved. If your management comes to you and asks you to commit a crime and you do anything other that say "no" then you are a criminal yourself. This is not complicated.
There's like an entire corporate machine in place to ensure that a lone wolf can't through error or malice can't cause problems. Things like basic software development practices should ensure that bad/stupid things don't go unnoticed.
This wasn't unnoticed. This was done intentionally and there were many people involved including more than a few engineers. We know the engineers knew about it because it apparently was a group of senior engineers who ultimately spilled the beans. If they knew and they said nothing then they are complicit in a crime and should see appropriate punishment in a court of law.
I am willing to bet that this engineering project was pulled of with a stunningly tiny cast of characters and a minimum of paperwork; which will make for an interesting contrast with the bureaucratic effort that would have been required to create such a "feature" through the regular channels.
If anything VW should learn from this how to efficiently engineer their cars into the future. But alas they will fire anyone who not only cheated but even worse didn't follow the practices and procedures laid out by people who had nothing better to do with their time than to layout and enforce practices and procedures.
It would only really require one or two people to pull this off. All the necessary components are innocent enough. (Also, the idiot who wrote the article is full of bull about "requiring additional hardware".) Components (with innocent purpose):
* Hardware necessary to detect testing mode: all cars have a speedometer
* Software to detect testing mode: reasonable to use for internal tests, and on production for traction control
* Hardware to allow software control of EGR: necessary for efficiency
* Software to adjust NOx/performance/efficiency levels: legitimate to have various modes, or for use in areas with different pollution laws
It would be trivial for one guy to write the code to have low NOx during testing, and high efficiency/performance otherwise. However, half the company would have to know they were cheating.
Don't waste your vote! Vote for whoever you want, unless you live in a swing state it won't matter anyways
VW use exhaust gas recirculation EGR as a core part of their emmisions control http://www.myturbodiesel.com/wiki/egr-system-faq-for-vw-and-audi-tdi/ . This is throttle-able to vary the amount of EGR for different loads and conditions and so can also be essentially shut off by the engine control system.
There are more then enough sensors on a modern car to sense test bed situations. There are accelerometers for the traction control and airbag systems that can sense lack of real acceleration during apparent acceleration on the speedometer. And there are steering wheel position sensor which has inputs for the traction control system.
All that is required to combine this information into a "defeat device" is some code.
Any ABS equipped car needs those for at least 3, and usually 4 wheels so that ABS works properly.
Any car built past ~1985 with electronic transmission speed sensors for the speedometer will do the job for you without ABS wheel speed sensors, even.
The author is entirely ignorant, and speaking from a position of feigned authority and research. He should be drowned in his own bullshit.
Just some clarification from an amateur ECU hacker, with extensive experience in direct OBD2/CAN comms with various controllers in cars (including VWs):
The various vehicle speed sensors (individual wheel speed/ABS, differential/transmission speed/speedometer, accelerometer/gyro for ESC) are not CAN-connected.
They connect into the various controllers directly (ABS/accel -> ABS/TC/ESC computer, speedo -> ECU)
The controllers themselves communicate over CAN.
Specifically here, the TC/ESC logic absolutely has its hands in engine performance. That's the principle method of traction control- limit engine output when traction is lost. Secondary remedial measures are automatic brake application.
Author is still an idiot.