Toyota's electronic throttle, and..

....just why Sudden Unintended Acceleration is virtually impossible.

<http://www.popularmechanics.com/automotive/how_to/4347704.html>

The author does not mention it, but the NHTSA closely regulates the design
of the electronic throttle and its firmware. It is, by design, not possible
to "hack" into the firmware in order to modify or disable it.

 

This is true to be sure. The fed has regulated and are culpable in any
court action. They know it too. Although the fed cannot be sued
directly, they can be called as witness. They would not like that much.
--

 

No. You'd have to have to have the pin that enables erasing/rewriting of
the EEPROM/EAPROM IC used and the hardware (electric and electronic) to
support it to be able to do it. One *could* however physically take the
ROM out and completely rewrite it, if you could rebuild the module you
destroy by doing this. That is entirely possible and anyone could do it
with enough technical knowledge, ability and the right pieces. Anyone
can buy a PROM programmer.

That's all beyond the scope of such an article of course, but it shows
what is involved in doing it sucessfully.

I'd bet good money that all race cars have a connector for just this
purpose.

 

The article was very good and I believe the conclusions are correct
(i.e., it is not the electronics). I do wonder about your statement.
Anything to back it up? Exactly how does NHTSA closely regulate the
design? The firmware is in the ECM, and people are constantly screwing
with that. My son has some sort of programer that allows him to screw
up the ECM in his Mustang (and I do mean screw it up). I looked at the
Toyota shop manual for the RAV4 and it appears to me all the throttle
control stuff is handled by the ECM, so I can't see how that is any
more secure than any of the other firmware.

Ed

 

Of course. And you could take a roll of sheet steel and turn it into a car
body; you could turn a steel billet into a fully-automatic firearm; you
could turn a bag of lawn fertilizer into a bomb.

Surely, but nobody's alleging tampering. Instead the allegations are of
defects from the factory, and that's where the silliness comes in.

 

A Toyota MDT told me this. He and his cohorts have received
extensive factory training on the electronic throttle as part of the normal
dealership-tech training. And they've had some very intensive additions
to that training on account of the recent controversies

Couldn't tell you. I can only relate what I've been told by my /very/
reliable source: The electronic-throttle firmware is NOT modifiable; its
circuitry is independent of anything else that might control the engine.

 

What you're talking about here is talking about is on the auto shows
fixup shows such as they have on SPEED TV. You're not actually erasing
the EPROM and then putting new machine language into it replacing what was
originally there. You're changing variables such as valve timing and so
on. This difference may only be apparent to people who *have* written
computer programs like myself. It can of course damage an vehicle just
as removing a rev limiter or boosting the engine with too much nitrous
will do. Nothing more.

 

Yes, that was partially my point. The other part was that there simply
is no way to flash the ROM like some trojan would do to some internet
noobs router.

Perhaps, I'll reserve my judgement on that until I see some real
conclusions in this Toyota mess. It could easily be minor bugs in the
actual ROMS however. Extremely doubtful, but always a possibility.

 

Why do you keep setting a Followup to rec.autos.tech? I only crossposted to
three groups, all of which have had extensive discussions regarding this
matter, and all which I thought would benefit from a discussion of the
article I originally referenced (and which only Ed White seems to have
actually read).

<http://www.popularmechanics.com/automotive/how_to/4347704.html>

 

Because I only read that group.

To further explain, my newservers are touchy about posting to numerous
groups without using a follow-up header, so I frequently error on the
side of caution. However being only three groups, I will desist if you
prefer.

 

That's fair. But I read all three.

Mine appears to be touchy as well. Not all my replies always appear in all
three groups. I've just asked my admin.

The three groups I crossposted to all have had discussions regarding the
throttle issue. I thought I had relevant information to pass on, and also
thought the expected subsequent discussion might prove entertaining and
enlightening for all, especially if it flushed out some new info that had
not been heretofore posted. If crossposting is removed, threads that
develop in the various groups become independent, none of them knowing what
happened in the other groups.

Having said that, it appears that most of the discussion has ended up being
in rec.autos.tech, so maybe I shouldn't have bothered crossposting in the
first place...

 

Now I'm not sure about Toyota, but there was something disturbing
about my daughters car, a 2005 Saturn Vue. GM had a recall on the CVT
transmissions in these. Of course, since they went through bankruptcy
GM believes that they no longer need to honor the recall, but anyway,
I will digress.....

The dealer replaced the transmission (GM did pay 50%), and for the
first few days, the car was fine. About 5 days after bringing the car
home from the shop, while in the garage she started the vehicle one
morning. The engine raced on it's own, and the speedo was reading
about 50 mph even though the car was in park and the pedal wasn't
being pressed. She turned it off, and called me in...and I started it
up and the same thing happened.

I called the dealer and explained what happened. The rep put me on
hold, came back about 3 minutes later and told me in no uncertain
terms not to drive the car (which I pretty much figured myself, duh),
they will pick it up. They were at my house with a tow truck within
half an hour, took the car and gave us a rental until another
replacement transmission arrived and was installed.

I've asked them numerous times what from the transmission would make
that happen...some kind of sensor with a feedback into the motor?
They would not give me a straight answer on this, but it sure makes me
wonder....

 

<press_release_keywords>
but but but, black box, dangerous, parts suppliers owned by toyota,
unattributed smear and bullshit...

 

good cite.

 

My wild guess is that you simply were not talking to anyone who actually
knew.

 

Well, their reactions to the problem were far too quick for me to
believe it was just good customer service. The dealer is a good 20-25
mins away, and they were there in 30 from the time I hung up the
phone. Even my daughter was saying "wow, they got here quick!", and
we had a freebie rental car not long after that.

While there may be "failsafe" mechanisms in place for sudden and
unwanted acceleration, just what would make the speedometer read at 50
MPH and the engine race while in park that would be part of the
transmission? Some kind of speed feedback sensor? I would have to
believe that if this happened while driving the vehicle, it could have
created a dangerous situation. My phone calls and emails to Saturn
have gone unanswered....but I will eventually find an answer.

 

Oh, I'm sure you got someone who could immediately talk to a tow truck
driver, but that certainly isn't the same as you talking to the actual
mechanic that worked on your car is it?

Anyone would know that it as a severe problem that would have to be
fixed immediately and made the vehicle unsafe. You just talked to
someone competent at the dealership is all.

As for actual *cause*, I'll leave that to the mechanics here, but I have
my doubts it could *only* be one thing.

 

Yes, it could have been a combination of things...but they replaced
the transmission they had just recently replaced. I guess I just need
to keep digging.

 

I was the unfortunate owner of Vue with the CVT transmission as well. I
also got a new transmission (and promptly traded off the car).

The control system on those cars was very complicated since the ECM altered
both the engine speed and the transmission gear ratio based on the vehicle
speed and accelerator pedal position. As a wild guess, I'd suspect the
vehicle speed sensor was hosed and the engine controller was attempting to
match the engine speed and transmission gear ratio to the false road speed
reading - even though the car was not moving.

In addition to the new transmission at around 38,000 miles, my Vue had also
had the transmission in for another recall early on. Basically GM just
screwed the pooch on that CVT. In theory it was a good idea, in practice the
GM design sucked. My parents had a Ford Freestyle with a ZF supplied CVT and
it never had a problem, so I know it can be done. I also think Nissans sells
a number of vehicles with CVTs and I don't recall hearing that those had a
lot of problems (ditto for Honda and Toyota). Maybe the GM CVT was just
overstressed behind a 2 liter engine.

I was actually satisfied with the Vue for the first 3 years I owned it. I
did have to take it in to have the CVT programmed during that time, but as
long as I was the principal driver it seemed OK. However, after my Son
started driving, the CVT didn't last three months. Neither did the horn, or
several other items. My final conclusion was that the Vue was designed for
little old lady school teachers.

Ed

 

Well, we did get 90k out of the first one.....not a record....but yes,
it is time for it to go.