[ale] [Slightly-OT] OBD-II in vehicles (Was: Re: Android Tablets)

[Jim Kinney]

On Mon, Aug 23, 2010 at 12:06 PM, Michael B. Trausch <mike at trausch.us>wrote:

>
>
> For that matter (this of course only applies to 1996 and newer vehicles,
> just as the CHECK ENGINE light only applies to 1996 and newer vehicles),
> if the MIL (Malfunction Indicator Light, a.k.a. CHECK ENGINE or SERVICE
> ENGINE SOON or the pretty little engine icon or whatever) is burned out,
> you will fail emissions.  Part of the test with OBD-II cars is that the
> test tries to turn on the MIL, and if it cannot do so, you fail without
> even going any further in the test, even if your car would otherwise
> pass emissions (e.g., OBD-II reports no trouble codes, reports full
> readiness, and all data is within the appropriate specs).
>
> This is been a source of annoyance for me---I very much wish that you
> could opt to shove the sensor up the car's ass even on 1996 and newer
> cars, because the computer really doesn't know everything.  Don't get me
> wrong, I *love* technology.  But I still vehemently believe that it
> doesn't have any place in cars.


At the point where the car makers get told "you must provide at a minimum
_this_ level of detail..." things will improve (I hope). What is needed is a
change in the way people think about the "idiot lights". If the oil light
comes on, it already too late. The older sensors didn't check for much
because 1. They didn't have to and 2. they couldn't.


>  I've seen cars where the computer
> reports everything is quite alright, but when you go down the road
> you're throwing tons of pollution in the form of smoke in the air.


I hate that! But (!) the smoke is not a "pollutant". This is a policy
failure.

I had an old car that the slush-o-matic transmission totally crapped out and
began spitting trans fluid up the vacuum line so it was being burned in the
engine. The cloud from the tailpipe was dense white and fairly toxic. But
from an EPA standpoint, allowed.

Burning oil smoke will also not trip the sensors as it is not on the air
pollution control list.


>  On
> the other hand, I've seen cars that the computer reported trouble on for
> a non-emissions related issue and they would then fail the test because
> OBD-II says "Not Ready" or says that there are stored codes.  That's
> absolutely ridiculous!
>

Ah!  The "Not Ready" means the system was "turned off" by pulling the
battery and it has to wait a certain number of miles/hours of engine
run-time to collect enough data to present a valid response. It's there to
stop people from faking a test. My gas cap kept coming loose and the check
engine light would come on. When tightened again it took 50+ miles before
that check was reran. Crappy design from Saturn. New one just as flakey.


> At least twice, on both sides of the coin, that's been my car.  There
> was a problem with the old engine that was in my Saturn that was dying,
> and it was throwing TONS of crap into the air, but because they didn't
> give it the "drive" test that they give to pre-OBD-II vehicles and the
> computer said that all was good, my car passed---even though it really
> should NOT have passed.


Yep!. Tailpipe is spewing crap but not the crap the sensors are looking for.
Maybe if someone ran a carcinogen test on burning oil smoke...


> And there have been times where it SHOULD have
> passed, but it didn't, and I had to do the hokey pokey thrice in
> opposite directions each time to get the car to finally pass, without
> making any repairs at all (or just having made repairs to it).
>
> Yet another field where technology isn't really helping as much as it
> could, I think.  For these reasons and more, I can't honestly recommend
> that anyone get a car that supports OBD-II in California.  The couple of
> people that I know out that way have told me that CA law actually
> requires that the cars transmit their OBD-II status while driving, and
> that there are little roadside sensors that collect the data.
> Essentially, emissions testing happens all the time that you're driving,
> and if you fail you get a certain time window in order to fix it.  How
> insane.  I'm all for cleaner air, and I'm all for technology to help
> achieve that goal, but I know that there are times when I can barely
> afford to buy the parts to fix my car myself, let alone pay a mechanic
> to do it---having a time constraint of "RIGHT FSCKING NOW" would be
> unreasonable.
>

The missing piece is intelligent text to the driver. Something that says -
"emissions sensors indicates a failure. emissions output is now X% over
allowed amount. You have Y miles to perform repairs to stay within legal
limits."

As a society, we still have to require that responsibility be enforced by
laws. Especially when there's money involved.

>
>        --- Mike
>
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-- 
-- 
James P. Kinney III
I would rather stumble along in freedom than walk effortlessly in chains.
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