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VAG - How did they get away with it for so long?

2K views 10 replies 4 participants last post by  115686 
#1 ·
This is purely speculation, but I believe there is merit in my analysis. It stems from the figures obtained wrt Lambda readings. I do not want to have to spend a lot of money, re- calibrating my AFR by way of expensive software modifications.

So I have been investigating wide - band Lambda Probes. Those fitted to the manifolds are Bosch LSU 4.2's and there is, as usual with Bosch, data sheets available to which engineers can refer.

The principle being that Stoichiometric represents an AFR of 14.7:1 air/fuel ratio. Now, according to my research, in terms of sensor voltage this equates to 350 milli - volts. Ultimately this is derived from the sensor current which is "Tuned" to 1 milli - amp. This voltage is determined as being central to the linear section of the sensor at Stoic. Any variation from this is a function of the "Cell Impedance", which varies depending upon the fuel/oxygen Ions across the "pump".

The Bosch Lambdas have an external calibration resistor, to compensate for manufacturing tolerances, the value of which is chosen to normalize the Pump Current to 1 milli - amp.

So I thought, if I was to increase or decrease the value of the calibration resistor, the closed loop system would cause the ECU to re - adjust the current in the loop to 1mA. So I could; at will, modify the AFR, and importantly, it would be applicable at all points across the rpm range.

Tonight, I had a quick pint with a friend of decades standing. He also happens to be a very senior marine engineer. He quickly picked up on what I was saying and simply stated, "So, you have been talking to VAG then! Switch resistance when your car is due an MOT or subject to compliance tests, then switch it out again, when in normal use?"

I was flabbergasted at the speed at which he grasped what it is that VAG appear to do. So simple, so inexpensive, yet so effective.

If anyone can suggest there is anything more to what VAG have done, I would appreciate the input. However, the next stage is to test the theory.
 
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#2 ·
They have an incredible arrogance in everything they do. Recently they supported the #never forget initiative about the Auschwitz prisoners being freed. With no reference to their part in taking prisoners months before and working them to death to build for them. They said it must never happen again months after it is found they were using prisoners to build VWs in China. When asked, the 8m dollar a year boss said he was” not aware”.They did create a new brand there so that the workers aren’t working for VW, it would appear. The latest round of promotions in Wolfsburg are hilariously un-diverse following publicity about diversity. And then there’s the non-available electric car shown in ads as “now” when they’re not available and having production problems. The first cars will be driven by the workers at the plant. 30 cars a day were coming off the line , without software and kept in fields until that’s ready.
 
#3 · (Edited)
“Q”, I can’t really answer that.

We, Historically, have been guilty of some appalling crimes against “Foreigners.

We introduced concentration camps in S.A., which ultimately led to the Boers walking out of the bush and surrendering, because their women and children were dying of disease and starvation.

We didn’t treat the Irish or the Scots too differently and peasant farmers were evicted from their holdings in East Anglia to man the Mills in Lancashire, Staffordshire and Yorkshire.

However, regulators today are in a better position to counter this than was the case when we “Ruled the Wave.

But, how did VAG get around emissions regulations - that is the question?
 
#4 ·
I think we keep a dignified silence when it comes to our past indiscretions but my point is that the people at the top don’t want to know. They just want it to happen. Bosch offered this to somebody below him and he was “ unaware”. At some level somebody accepted the effect of the cheat.
 
#5 ·
But all people at the top, don’t want to know! That is why we have perpetual instances of abuse of position in office.

Technical and public reports are written such that at the front is a summation of evidence. But it can be absolute bull Shyte wrt the evidence contained within.

And those charged with drawing conclusions can conveniently neglect to read the detail.

Even Blair’s Iraq enquiry had clear guidelines as to what could and could not be investigated.

But this still doesn’t answer the question, what did VAG do to circumvent the regs?
 
#7 ·
It was nothing to do with anything as simple as fooling the lamda sensor. ......way more complicated and clever than that....the cars were clever enough to know when they were undergoing emissions testing and effectively went into a lower power mode to pass them. This is from the official report.

Volkswagen installed emissions software that allows them to sense the unique parameters of an emissions drive cycle set by the Environmental Protection Agency. According to the EPA and the California Air Resources Board, which were tipped off by researchers in 2014, these so-called “defeat devices” detect steering, throttle, and other inputs used in the test to switch between two distinct operating modes.

In the test mode, the cars are fully compliant with all federal emissions levels. But when driving normally, the computer switches to a separate mode—significantly changing the fuel pressure, injection timing, exhaust-gas recirculation, and, in models with AdBlue, the amount of urea fluid sprayed into the exhaust. While this mode likely delivers higher mileage and power, it also permits heavier nitrogen-oxide emissions (NOx)—a smog-forming pollutant linked to lung cancer—up to 40 times higher than the federal limit. That doesn’t mean every TDI was pumping 40 times as much NOx as it should. Some cars may emit just a few times over the limit, depending on driving style and load
 
#8 ·
Right! So it is that simple!

How long did it take to perfect this little ruse? Software fails at so many simpler levels, so to make this work, surely took the minds of geniuses.

But to do it, is tacit acknowledgment that on a basic level, their cars would all fail to meet regulations. How could they be so far off the mark to end up in that situation?

Were the problems related to only Turbo Diesels? Nox generation being a function of higher temperatures, higher compression ratios and higher charge fills - higher specific power outputs, but Nox can be converted effectively by good exhaust design - lowering exhaust temperatures in conjunction with cats, and particularly with Diesels, EGR. Or so the research papers I have read indicate.

It beggars belief, that they should ignore all the research, a lot of it by eminent German scientists.
 
#10 ·
So, we can all cheat when it suits us - sorry, stretch the parameters to notionally comply!

Well I'm not going to go down the VAG route - well perhaps for my own amusement and to satisfy my curiosity. So this is what I propose :-

To do this however, I need to get hold of a couple of connectors from failed/cast LSU 42 - 3.2 JTS manifold Lambdas. whilst the harness connectors are available, Those fitted to the Lambdas are not. And, as I want to avoid cutting/ modifying my harness, I need to make up an interconnecting cable to apply my modification.

However, from the attached picture the 30 - 300 ohm resistor is "R cal". This are fitted inside the lambda connector and is laser cut to adjust the Current - sense to 1 mA. This sets the Lambda Stoichiometric figure of 14.7:1 AFR at the linear section of the lambda response curve. It corresponds to 350 milli volts according to articles I have read.

A lean sense from the exhaust gases will result in too much oxygen, a rich sense too little. Either condition will cause the Current Sense to move above or below 1 mA loop current and the control circuit will act to restore it, and in doing so the ECU will adjust the fuel quantity, to lean or richen up the AFR back to the Stoichiometric. It does not have to be absolutely 14.7:1, it will be whatever figure the system designers have chosen.

So my intention is to test the laser cut resistive value of R - cal, in my lambdas and configure the interconnecting cables with resistive values which enable R - cal to be modified above and below its laser - cut value. These test resistors will need to be calibrated to ensure the changes are equal for both banks.

However, causing R - cal to reduce will increase the current sense above 1 mA, and the ECU will respond by reducing the fuel injected. Causing R - cal to increase, will reduce the current sense below 1 mA, and the ECU will respond by increasing the fuel injected.

S.O.T. resistors can be of various values, switched in or out via a Rotary Dual Wafer Switch. Whatever values are chosen, the ECU will act in such a way to restore the Current Sense back to 1 mA with whatever S.O.T. values are in circuit, via the rotary switch

In adopting this approach, the AFR will be modified right across the engines range.
 

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#11 ·
Why would you want the lambda to report incorrect readings across the range?

I can see why you might want to lean out in cruise, with your delta controlled by EGT or similar - which is what light aircraft do (manually).

But when you floor it, you want the right answer. Otherwise you'll be spoofing the map to compensate.
 
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