

Government investigation: No evidence Toyota electronic throttles malfunctioned - m_myers
http://www.reuters.com/article/2011/02/08/us-toyota-usa-idUSTRE7165SY20110208

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mrcharles
Anyone else kind of scared by the fact that there's 280000 [0] lines of code
in a car? I mean, I know there's computers in there, and that they are
necessary nowadays, but that seems like an awful lot of code to handle some
lights and engine timings.

[0] [http://detnews.com/article/20110208/AUTO01/102080381/Feds-
cl...](http://detnews.com/article/20110208/AUTO01/102080381/Feds-clear-Toyota-
of-electronic-causes)

~~~
momotomo
No. Two perspectives on this - currently working alongside Process Control
Engineers, and I'd trust these guys to do this kind of work. The mindset and
level of detail is complete different from programming in non-critical fields.
Our peer review process is comprehensive, and mandatory for all code changes,
can be typical for 2+ weeks of dedicated review and analysis on small scopes
of change.

Secondly, theres a _lot_ in an ECU. I recently installed a custom ECU into my
streeter (Autronic SM4), and the volume of control you have (3D F/A ratio
maps, 3D ignition timing, cold start control, knock sensing, fuzzy logic for
wear compensation such as dirty injectors / plugs etc) is staggering. On top
of this you have exception management (like limp home mode if you blow
something up).

It's just like any other programmable logic controller. Additionally for cost
savings they probably run the one codebase across a few different models, so
not all of it would be executed code.

~~~
nickpinkston
Ever use the Megasquirt system? I put one together a while back, but never got
to actually get it hooked up to the engine. How's the Autronic?

~~~
momotomo
Have heard of / but haven't used MS. Autronic install will actually be
completed by 11/02. They're comparatively cheap and feature complete (3d maps,
realtime tuning compensation, boost management etc). Had it recommended by a
lot of people so far, and my local shop can tune them =)

At this stage it's a waste, car is stock, but using the lead time to learn the
tuning. Next phase is supercharging + NOS kit and related top end work, little
bit excited for it.

How is the MS actually structured, seems to have a few components to it?

~~~
nickpinkston
Yea, I believe the MS uses these sensors: Manifold Pressure, RPM, Intake Air
Temp, Coolant Temp., and throttle position - to determine everything. It's
very straight forward and pretty hackable - but I never actually did anything
other than hook it to the "Stimulator" which was a board that acts as an
engine to test the MS unit.

I also used the HPTuners software to tweak my fuel / spark maps on my stock
ECU, and it worked very well actually. Good luck with your project!

------
misterbwong
This doesn't mean that Toyota was in the right all along. I still think they
got a bad rap for what happened, but apparently I'm in the minority.

More context:

The probe by National Highway Traffic Safety Administration and NASA engineers
found that the only causes of the unwanted acceleration were the previously
identified sticking accelerator pedals and loose floormats that could jam the
pedals.

~~~
yason
The floormats are pretty obvious and that has happened before. Given that, how
hard is it then, if your car doesn't stop accelerating, to simply push the
clutch down or switch to neutral, depending on your type of transmission?

~~~
lutorm
My VW will cut the gas if you are pushing on both gas and brake at the same
time. That also seems like a reasonable prioritization.

~~~
cma
That adds complexity; it could falsely trigger when someone was making a left
turn in front of oncoming traffic causing them to stall and get creamed. Not
saying it isn't still the best choice, but it does have potential downsides.

~~~
yason
Who will ever press the brake pedal with their _left_ foot? That sounds like
remixing all the routes of neural impulses for braking/accelerating.

I sometimes do it consciously on a parking lot after a good car wash during
winter to slightly warm and dry the brake pads to prevent them from getting
frozen, and I have to carefully think my foot-pedalling logic twice--no, three
times!--to only apply a slight pressure on the brakes while my right foot
keeps pushing the accelerator.

If I did that during driving in the traffic, I'd probably alternate between
jumping to a 100% halt and rear-ending somebody with screaming tyres.

~~~
cma
I was saying adding the mechanism adds complexity and the mechanism could
fail; I was not saying we should worry about the person pressing both pedals
at the same time during a turn.

