Tell ya what, you give me a good citation on whatever Honda
is proposing be flown-by-wire, and I'll give you meaningful
So far, I think people haven't any clue as to what's under
I was taught this once, but like other stuff we don't use, you forget it go
in a general since, it works like this:
In the GM throttle body, it has 3 electronic signals to compare to, one
being a mirror of itself. If it looses two of them then there may be an
issue (I believe) If you were to have an catastrophic failure, the car goes
to limp home mode and gives you a crawl speed.
I've not seen any redundant sensors in any GM vehicle I've worked on. My
current '97 truck with the 7.4l Vortec V8 certainly has no redundancy in
it's sensors. A single sensor each for throttle position, intake air
temperature, mass air flow, etc. Certainly if it looses one of the
sensors to the extent it can detect it, it will enter limp mode, but
absent redundant sensors, there are failure modes that the computer has
no way to detect.
you're tooling along at 20% throttle, 2k rpm. you want to accelerate
and go to 100% throttle. but your engine's only good for wot above 4k
rpm. you need to shift. but it's a stick and you don't. but you do
get some pull up to about 60% throttle. why throw away 40% that's not
being utilized? electronic control saves you gas.
ok, so you don't drive a stick, but you have an old hydraulic automatic.
again, you want to go up a steepish hill and because it won't pull at
low rpm's, you need the transmission to shift. it won't until you kick
it to the floor because the transmission can't detect load, only whether
you've operated the kickdown. sure, you can manualy over-ride, but why?
electronic controls know exactly the engine load and can therefore
determine the grade of hill. selection of gear ratio and throttle
position is /much/ better.
besides, what's with this misconception that we need direct throttle
linkage? anyone here ever worked on diesels? anyone here know that the
diesel govenor does? there's no direct linkage to fuel injection on a
diesel - it's all done by the govenor. if that thing fails, you have
ZERO engine control. diesels have been like this from day 1.
Wrong. Remember the vacuum operated modulator valve? They worked great
until the diaphram broke and ATF got sucked into the engine. Those were
the days, man, those were the days....
sure, you can manualy over-ride, but why?
Few use manual transmissions now, and even if they did, the 'by wire'
would not change a thing.
Even with diesels, 'by wire' actuation does nothing unique.
IF automated highways ever became a reality, then a totally electronic
might be the way to go...collision avoidance, route selection, traffic flow
police interception, etc...all might be controlled by computer...
I think I will stay home if that ever happens...
OK, Sparky... You've been itching for it, so here it is - *MY*
application of "ain't technology wonderful?!?":
(It's called a killfile - It's a sort of "storage area" for morons and
fools who have nothing useful to say, but insist on running their
clueless mouths anyhow - Say "buh-bye", Sparky... You no longer exist in
my world. Which is a great improvement over 5 minutes ago.)
Don Bruder - firstname.lastname@example.org - If your "From:" address isn't on my whitelist,
or the subject of the message doesn't contain the exact text "PopperAndShadow"
I'm not sure about the Honda system, but the GM system allows
the computer to use the throttle to make other things that are
happening transparent to the driver. I know that the new v-8's
with the 4-8 cylinder technology use the electronic throttle to
make the shift from 4-8 cylinder transparent. The electronic
throttle is also used to "improve" tranmission shift quality.
There are bound to be all sorts of good reasons why you want
to control the throttle. Personally, as a tech that works on
the vehicles, I hate the fact that I can no longer "blip" the
throttle under the hood. I can use a scan tool to change
rpm, but there is no way, other then using a helper, to
rev the engine quickly anymore.
I also find that many of the vehicles have a very "disconnected"
feeling from the throttle. Some are better then others, so I'm
sure it's just a matter of tweaking the calibrations.
Now when it comes to "steering by wire".....I'm not sure
that I'd be in favour of that.
I wouldn't worry about not having a mechanical connection.
We have had electronic throttles for a long time with very few
problems. We have also had hydraulic brakes since the 1930's with very
very few problems of total failure.
Yet brakes still fail now and then, from lines going bad, slipping,
My only question, however, was regarding the steering should power be
lost. I have had experience with an engine going offline while at
speed, and would prefer to maintain some steering control if I ever
found myself in a similar situation! Dittos for you or anyone else hwo
happened to be out on the road with me. I still am not sure about
whether Honda has or is going to have DBW steering, and as for
throttle, I asked at another dealership today. None of the sales staff
really had any specifics on how DBW throttle works, or if they are
going to do steering that way. The write up book I saw on the features
and specifications for the forthcoming Honda SI Civic (Which I had
heard would have it at the other place) had no mention at all of any
DBW throttle or features. If they are trying to "slip it in there" like
that at Honda, that's pretty sneaky. Truth be known, if the one
salesperson hadn't told me, I might never have known to ask.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.