6 ms·

Is there any detailed information anyone can find on what they allegedly did, at a technical level? "Defeat device" is such a broad category of term that it's

by Syonyk 3y ago

Is there any detailed information anyone can find on what they allegedly did, at a technical level? "Defeat device" is such a broad category of term that it's useless for understanding the details of what it's claimed they did. The Justice.gov writeup [0] isn't any better. > The company allegedly installed defeat devices on 630,000 model year 2013 to 2019 RAM 2500 and 3500 pickup truck engines. The company also allegedly installed undisclosed auxiliary emission control devices on 330,000 model year 2019 to 2023 RAM 2500 and 3500 pickup truck engines. I'd be interested in reading technical details on what, exactly, they did or didn't supposedly do. [0]: https://www.justice.gov/opa/pr/statement-attorney-general-merrick-garland-agreement-principle-cummins-settle-alleged https://www.justice.gov/opa/pr/statement-attorney-general-me...

kotaKat 3y ago
Best I have off hand is one of the example recall notices which just says "software update" for the emissions calibration: https://www.chrysler.com/universal/webselfservice/pdf/VB6.pdf https://www.chrysler.com/universal/webselfservice/pdf/VB6.pd...
Guvante 3y ago
IIRC other manufacturers would detect the usage pattern of tests and run cleaner as a form of bypass. Similarly you could lie on the OC2 response.
- Syonyk 3y ago
  Sure, I know what other manufacturers did. I want to know the technical details of what Cummins allegedly did "enough that they're not arguing a massive fine, while claiming they didn't do it on purpose." Claiming they "installed defeat devices" isn't nearly enough detail. How did it alter either the engine combustion cycle or the emissions control system behavior?
  - rightbyte 3y ago
    Who knows? I believe VW chief engineers got in jail not knowing what their subordinates did. I really tried to understand the VW scandal but I could not.
    - Syonyk 3y ago
      When operating an engine (gasoline or diesel), you can make a range of decisions about how you run it. Fuel/air ratio, ignition timing, exhaust gas recirculation amounts, boost pressure, etc. There are a lot of ways to accomplish a given power output, and generally some will be more or less efficient in terms of fuel quantity used, and some will be better or worse for emissions. You'll usually find that "optimum for one" is not "optimum for all," and so the ECU (engine computer) has to decide where to run the engine for any given situation. The (increasingly invalid) assumption made by the EPA test cycles for emissions is that "What it does on the test treadmill will generally reflect what it does on the road." So they've got some (well known) set of drive cycles that reflect a range of driving conditions, they put a car through its paces on the treadmill, and this (a) validates that the car meets the relevant emissions standards, and (b) gets you the EPA-rated miles per gallon. Probably other stuff too, but these are the important ones. VW violated, quite intentionally, the "behaves the same in the test chamber as on the road" assumption. Every time the car was started, it would assume it was being tested for emissions, until something "impossible in a test chamber" happened (like the steering wheel was turned - you don't do that on rolling road treadmills). At that point, once it was confident it wasn't being tested, it would alter the engine maps to be rather a good bit more fuel efficient - but at the cost of NOx (oxides of nitrogen) emissions being also far higher. So, on the road, the result was that the cars beat their EPA rated fuel economy (which is odd - nobody ever does that, as the real world has things like wind), but also violated the emissions regulations they were certified under (while also putting out less CO2 - because it used less fuel than rated for those conditions). And they got away with it for quite some while.
  - lmm 3y ago
    Most likely they've been caught with memos saying to install a device that would trick past the test. It doesn't really matter what the devices did on an engineering level or even whether they worked at all, and the regulator may not even know or care; the hard part in a case like this tends to be showing criminal intent.
oooyay 3y ago
I'm guessing they're doing it during state emissions certification. When they do those tests they hook up to your OBD2 port [1] and generally a tube goes onto your exhaust. It'd be pretty trivial to detect, "Cable is hooked up, exhaust has more back pressure. Tune engine to X mode." 1: https://www.progressive.com/answers/what-is-car-emissions-test/ https://www.progressive.com/answers/what-is-car-emissions-te...
- Scoundreller 3y ago
  I thought they went away with the tube testing once the OBD data got good enough. Trick to passing the tube tests was to take your vehicle on a nice long ride to get hot (especially the cat). What I disliked about state emissions testing is that they didn’t do analysis/sampling of data to take an evidence-based approach to target testing against vehicles that tended to fail.
  - Syonyk 3y ago
    It depends on the vehicle and state. In general, "tube testing" went away on gas cars when OBD-II was standardized - they just ask the car, "Are you happy with your emissions system condition?" and accept the answer, though it's not utterly trivial to forge the answer. The fundamental problem with all the emissions testing is the gap between "as it's supposed to be done" and "as it's actually done." The people actually doing the work tend to be, more or less by definition, "car people." And they reasonably enough tend to avoid the more "engine abuse" ends of the test spectrum when they can do so - which does reduce the effectiveness of the tests in some cases. For older diesels (my '97 7.3 Powerstroke, for instance), the "snap test" is supposed to involve flooring the throttle and letting the engine bounce off the rev limiter, while the sniffer sees how much smoke you emit (with a comically high pass limit - something like 40% opacity, which is really "a very dark exhaust plume"). The one and only time my engine has seen the rev limiter in my car was when I emissions tested it shortly after buying it, and did the procedure as written. Every other time I've tested it, someone else has run the test, and they'll bring the engine up quickly (but not floored) into the test RPM range, which doesn't involve going to redline - think 1800-2000 RPM instead of 3500 RPM. They way they do it, you pretty much can't fail if you drove the truck there, unless you've got a check engine light glowing or obviously missing emissions control equipment (no bulge in the exhaust pipe where the cat should be). Because the people doing the test, very reasonably, don't want to be responsible for older engines throwing rods out the side of the block, and there is zero reason to have a lot of the older diesels at redline, no matter what you're doing (I'll let the engine spin to 3k when I'm pulling a heavy trailer up a long grade, otherwise I never even see 2500 RPM). And there's also the various "ways around the test." A friend who used to have a rather fun to drive car noted that his sniff tests always resulted in the emissions profile of his mechanic's very clean, stock, Honda Civic. There's only so much you can do, unfortunately, when people are motivated to go around the edges of the system. And I'm not sure "clamping down massively" accomplishes much at this point.
spacecadet 3y ago
Engine computers can easily be reprogrammed to make the engine run at all sorts of different operating bands. You could easily detect state emissions equipment, since it must pull information from the ECU. To me- these devices are either pre-programmed operating modes that produce clean emissions but the vehicle would not operate under this tune (emissions testing is often not under load) and so once back on the road, returns to the original operating mode. OR, entirely fake modules created to trick emissions systems without altering the operating mode. PS check out Megasquirt if you want to learn about DIY Fuel Injection. I ran a home brew Megasquirt/Megaspark system off an IBM laptop in my Volvo 740 Turbo back in the 90s, one of the things that got me into hardware.
- dcormier 3y ago
  VW's detected emissions testing when the steering wheel was never turned.
  - spacecadet 3y ago
    Makes sense. As I said, emission testing is often not performed when the vehicle is being driven/under load. States could incorporate dyno testing, but its technical, complicated, and unsafe.
  - deleted 3y ago
    [deleted]
  - Fatnino 3y ago
    Is that what it was? I though it was when the car is on a dyno only the drive wheels turn while the other 2 are stationary.
    - spacecadet 3y ago
      You are correct, the steering wheel approach is very smart... all I was suggesting was that dyno testing would limit the ability to defeat, but testing stations would also need to simulate more of the vehicles systems.
- 3y ago
calamari4065 3y ago
It's actually surprising to me just how differently an engine can perform with different tuning. The ECU can control all sorts of parameters depending on the engine. Things like fuel/air mix, ignition timing, valve timing, shutting down some cylinders, skipping ignition cycles, a lot more than you'd ever expect. You can tune an engine to sound like a braap braap muscle car or have it be nearly silent. You can burn all your fuel to get a few more horses or blow black smoke, or you can tune it to consume no fuel, emit nothing, and produce nearly no torque. Plenty of people tune their engines with aftermarket kit and/or software. There are even simple plug and play kits of extremely dubious quality any average Joe can install. What these defeat devices do is detect the testing equipment or conditions and tunes the engine in a way that meets requirements. Once the vehicle is out of testing, it reverts to the factory tuning which usually gives more power at the cost of illegally high emissions. That's really all it is, there's not too much magic involved. Just simple cheating.

by Syonyk 3y ago

kotaKat 3y ago

Best I have off hand is one of the example recall notices which just says "software update" for the emissions calibration: https://www.chrysler.com/universal/webselfservice/pdf/VB6.pdf https://www.chrysler.com/universal/webselfservice/pdf/VB6.pd...

Guvante 3y ago

IIRC other manufacturers would detect the usage pattern of tests and run cleaner as a form of bypass. Similarly you could lie on the OC2 response.

Syonyk 3y ago
Sure, I know what other manufacturers did. I want to know the technical details of what Cummins allegedly did "enough that they're not arguing a massive fine, while claiming they didn't do it on purpose." Claiming they "installed defeat devices" isn't nearly enough detail. How did it alter either the engine combustion cycle or the emissions control system behavior?
- rightbyte 3y ago
  Who knows? I believe VW chief engineers got in jail not knowing what their subordinates did. I really tried to understand the VW scandal but I could not.
  - Syonyk 3y ago
    When operating an engine (gasoline or diesel), you can make a range of decisions about how you run it. Fuel/air ratio, ignition timing, exhaust gas recirculation amounts, boost pressure, etc. There are a lot of ways to accomplish a given power output, and generally some will be more or less efficient in terms of fuel quantity used, and some will be better or worse for emissions. You'll usually find that "optimum for one" is not "optimum for all," and so the ECU (engine computer) has to decide where to run the engine for any given situation. The (increasingly invalid) assumption made by the EPA test cycles for emissions is that "What it does on the test treadmill will generally reflect what it does on the road." So they've got some (well known) set of drive cycles that reflect a range of driving conditions, they put a car through its paces on the treadmill, and this (a) validates that the car meets the relevant emissions standards, and (b) gets you the EPA-rated miles per gallon. Probably other stuff too, but these are the important ones. VW violated, quite intentionally, the "behaves the same in the test chamber as on the road" assumption. Every time the car was started, it would assume it was being tested for emissions, until something "impossible in a test chamber" happened (like the steering wheel was turned - you don't do that on rolling road treadmills). At that point, once it was confident it wasn't being tested, it would alter the engine maps to be rather a good bit more fuel efficient - but at the cost of NOx (oxides of nitrogen) emissions being also far higher. So, on the road, the result was that the cars beat their EPA rated fuel economy (which is odd - nobody ever does that, as the real world has things like wind), but also violated the emissions regulations they were certified under (while also putting out less CO2 - because it used less fuel than rated for those conditions). And they got away with it for quite some while.
- lmm 3y ago
  Most likely they've been caught with memos saying to install a device that would trick past the test. It doesn't really matter what the devices did on an engineering level or even whether they worked at all, and the regulator may not even know or care; the hard part in a case like this tends to be showing criminal intent.

oooyay 3y ago

I'm guessing they're doing it during state emissions certification. When they do those tests they hook up to your OBD2 port [1] and generally a tube goes onto your exhaust. It'd be pretty trivial to detect, "Cable is hooked up, exhaust has more back pressure. Tune engine to X mode." 1: https://www.progressive.com/answers/what-is-car-emissions-test/ https://www.progressive.com/answers/what-is-car-emissions-te...

Scoundreller 3y ago
I thought they went away with the tube testing once the OBD data got good enough. Trick to passing the tube tests was to take your vehicle on a nice long ride to get hot (especially the cat). What I disliked about state emissions testing is that they didn’t do analysis/sampling of data to take an evidence-based approach to target testing against vehicles that tended to fail.
- Syonyk 3y ago
  It depends on the vehicle and state. In general, "tube testing" went away on gas cars when OBD-II was standardized - they just ask the car, "Are you happy with your emissions system condition?" and accept the answer, though it's not utterly trivial to forge the answer. The fundamental problem with all the emissions testing is the gap between "as it's supposed to be done" and "as it's actually done." The people actually doing the work tend to be, more or less by definition, "car people." And they reasonably enough tend to avoid the more "engine abuse" ends of the test spectrum when they can do so - which does reduce the effectiveness of the tests in some cases. For older diesels (my '97 7.3 Powerstroke, for instance), the "snap test" is supposed to involve flooring the throttle and letting the engine bounce off the rev limiter, while the sniffer sees how much smoke you emit (with a comically high pass limit - something like 40% opacity, which is really "a very dark exhaust plume"). The one and only time my engine has seen the rev limiter in my car was when I emissions tested it shortly after buying it, and did the procedure as written. Every other time I've tested it, someone else has run the test, and they'll bring the engine up quickly (but not floored) into the test RPM range, which doesn't involve going to redline - think 1800-2000 RPM instead of 3500 RPM. They way they do it, you pretty much can't fail if you drove the truck there, unless you've got a check engine light glowing or obviously missing emissions control equipment (no bulge in the exhaust pipe where the cat should be). Because the people doing the test, very reasonably, don't want to be responsible for older engines throwing rods out the side of the block, and there is zero reason to have a lot of the older diesels at redline, no matter what you're doing (I'll let the engine spin to 3k when I'm pulling a heavy trailer up a long grade, otherwise I never even see 2500 RPM). And there's also the various "ways around the test." A friend who used to have a rather fun to drive car noted that his sniff tests always resulted in the emissions profile of his mechanic's very clean, stock, Honda Civic. There's only so much you can do, unfortunately, when people are motivated to go around the edges of the system. And I'm not sure "clamping down massively" accomplishes much at this point.

spacecadet 3y ago

Engine computers can easily be reprogrammed to make the engine run at all sorts of different operating bands. You could easily detect state emissions equipment, since it must pull information from the ECU. To me- these devices are either pre-programmed operating modes that produce clean emissions but the vehicle would not operate under this tune (emissions testing is often not under load) and so once back on the road, returns to the original operating mode. OR, entirely fake modules created to trick emissions systems without altering the operating mode. PS check out Megasquirt if you want to learn about DIY Fuel Injection. I ran a home brew Megasquirt/Megaspark system off an IBM laptop in my Volvo 740 Turbo back in the 90s, one of the things that got me into hardware.

dcormier 3y ago
VW's detected emissions testing when the steering wheel was never turned.
- spacecadet 3y ago
  Makes sense. As I said, emission testing is often not performed when the vehicle is being driven/under load. States could incorporate dyno testing, but its technical, complicated, and unsafe.
- deleted 3y ago
  [deleted]
- Fatnino 3y ago
  Is that what it was? I though it was when the car is on a dyno only the drive wheels turn while the other 2 are stationary.
  - spacecadet 3y ago
    You are correct, the steering wheel approach is very smart... all I was suggesting was that dyno testing would limit the ability to defeat, but testing stations would also need to simulate more of the vehicles systems.
3y ago

calamari4065 3y ago

It's actually surprising to me just how differently an engine can perform with different tuning. The ECU can control all sorts of parameters depending on the engine. Things like fuel/air mix, ignition timing, valve timing, shutting down some cylinders, skipping ignition cycles, a lot more than you'd ever expect. You can tune an engine to sound like a braap braap muscle car or have it be nearly silent. You can burn all your fuel to get a few more horses or blow black smoke, or you can tune it to consume no fuel, emit nothing, and produce nearly no torque. Plenty of people tune their engines with aftermarket kit and/or software. There are even simple plug and play kits of extremely dubious quality any average Joe can install. What these defeat devices do is detect the testing equipment or conditions and tunes the engine in a way that meets requirements. Once the vehicle is out of testing, it reverts to the factory tuning which usually gives more power at the cost of illegally high emissions. That's really all it is, there's not too much magic involved. Just simple cheating.