Monday, November 23, 2015

VW's In A Fix With Their Fix

Back in September, the U. S. Environmental Protection Agency (EPA) accused Volkswagen of cheating with regard to emissions controls of many of its cars that use diesel engines.  VW admitted as much, its CEO resigned, and now the firm faces the problem of fixing all the cars that violate emissions standards.  One way or another, some 11 million cars worldwide are implicated, with about half a million in the U. S. alone.  How did VW get into this fix, and how are they going to dig themselves out?

As new information has emerged on exactly how the cheating was done, it's pretty easy to tell that this was no single-line software tweak by a lone rogue engineer.  According to a Nov. 4 BBC report, someone (probably several someones) designed software to detect when the car was on a test stand designed for EPA checks.  This typically involves running the car while it is on a dynamometer, which uses rollers underneath the wheels to load the engine to simulate actual road conditions.  But in order for the stationary test equipment to be connected to the vehicle, the car is usually sitting still in a laboratory somewhere during the test.  I'm not saying that I know how the software guys did it, but if I were faced with the problem of how to figure out if a test-stand situation like this was going on, I'd look at the built-in accelerometers that every airbag-equipped car has.  If nobody's at the steering wheel and the car isn't going anyplace even if it's in "drive" and the engine's running, chances are it's on a test stand. 

However they did it, when an emission-test situation was detected the car switched into a mode that made it pass the emissions test.  But the price was severely crippled power and lowered engine performance, which however would not typically show up on an emissions test—after all, nobody's actually driving it to tell.  Once the test was over, the software readjusted the engine settings to produce normal power and performance—and as much as forty times more nitrous oxides (NOx) than the EPA allows.  But hey—it passed the test.  That's all that counts, right?

This mode of cheating is why fixing the problem with many diesel models, especially older ones, is not going to be some simple reload-new-software exercise.  If you've gone on a road trip recently and looked around in a truck-stop convenience store, you may have noticed piles of plastic bottles full of something called "diesel exhaust fluid."  Turns out that this stuff is now needed for many tractor-trailer diesel engines in order to meet the EPA's requirements for NOx emissions.  There's machinery on board the truck that squirts the fluid—which contains urea—into the exhaust, and the urea solution vaporizes to form ammonia and carbon dioxide.  The ammonia, in the presence of a catalyst in a thing called a selective catalytic reduction system (SCR), combines with the nasty NOx molecules to form nitrogen and water, which finally leave the exhaust pipe and rejoin Mother Nature, leaving her nearly as pristine as she was before the truck came by. 

It's one thing for truck engineers to see the regulations coming down the pike, and take time to redesign the power plant so as to accommodate another anti-pollution system which requires valves, heaters to keep the urea solution from freezing, pipes, level-monitoring systems, and all the other stuff needed to do the NOx-killing job.  It's quite another thing for VW to be under the gun to retrofit small diesel passenger cars that are maybe four or five years old, with a kit of SCR stuff they were not designed to have.  You'll need someplace to stick the SCR unit in the exhaust line, a way to get a pipe from the SCR to the urea tank, a place to put the urea tank, control lines, etc.  Engineers estimate the cost per vehicle could range up to $1000 or more.  With some cars, it may be cheaper for VW simply to buy them back from the owners and send them to the scrapyard.  Software-only fixes may be possible for some diesel models, but it looks like millions of cars worldwide will need expensive hardware installations to meet current emissions requirements.

VW says its internal investigation into how all this happened is still continuing.  For their sake, I hope they wind it up pretty soon, at least well enough to publish a timeline with names and actions.  But even without such information, it's obvious by now that deception with regard to emissions controls was an established policy.  Maybe the conspiracy—that's not too strong a term at this point—was concealed from upper management, and that's one of the things we need to know.  But even if it was, it's clear that there was a group of engineers inside VW who deliberately set out to cheat the system of pollution controls.  And they got away with it for several years.

It's not often that such a clear-cut case of wrongdoing by engineers makes the headlines.  Far more often, engineers will face a dilemma in which either choice has advantages and disadvantages, both morally and otherwise.  And sometimes engineers make the wrong choice, basing their decisions on incomplete information.  But in most engineering situations, information is always incomplete.  There's always more you'd like to know, but at some point the project must go on, choices must be made, and sometimes they turn out to be wrong ones.

But the VW emissions case is different.  Deception was intended from the start.  I don't know what internal company dynamics brought pressure to bear on engineers to the extent that developing a software evasion of emissions controls seemed like a good idea, but clearly something was wrong with the way ethical principles were stated and handed down. 

Sometimes, companies who do bad things are unrepentant and fight tooth and nail despite being in the wrong.  In such cases, large government fines are sometimes the only thing that will make an impression.  But in VW's case, its CEO resigned, sales are dropping, and there are news stories with graphics that show the famed chrome VW emblem breaking apart.  It's starting to look like the market and news media will do more punishing than the EPA is likely to do.  Whether that's fair or not is almost beside the point.  To survive, VW will have to own up fully, fix the mess it made to the best of its ability, and be a different company from the inside out—from now on.

Sources:  An Associated Press article on the types of fixes needed by VW was published in numerous outlets, including the U. S. News and World Report website on Nov. 19 at  Information on the details of how the cheating software worked was carried by the BBC on Nov. 4 at  I also referred to the Wikipedia article on diesel exhaust fluid.  I last blogged on the VW emissions scandal on Sept. 21, 2015.

1 comment:

  1. The ethical void goes way back with VW. If you look at the " valve stem seal material problem" that occurred in the 1970's and the way it was handled by VW you can see the same lack of ethical behavior.