Drive by wire (DBW)????

Can you tell me what "Drive by Wire" is please, on new honda accord
2.2i-CTDi, thanks.

Haven't heard of that, cheers.

AE

 

Control of something by electrical impulse over a wire rather tugging on a
cable-- like in the old days there was one from your gas pedal to the
butterfly in the carburetor that opened it wider when you stomped down. When
you tromp on the gas pedal these days, it sends a signal to the fuel
injector and fuel pump to step up the flow.

 

the steering is actuated by an electric motor that is controlled by a servo
actuator loop at the wheel. They're trying to eliminate the power steering
pump and reduce load on the engine.

IMO,not a good idea;if something glitches or fails,it WILL kill you.
There's a reason FlyByWire F-16s got the nickname "Yard Dart".

On an F-16,F-15,F/A-18,you gain a lot of maneuverability,something
important for fighter jets,but totally unnecessary for an auto.

 

actually,the ECU makes the injectors stay OPEN (duration) longer,thus more
fuel flow.(by sensing throttle pedal position with a variable resistor)

 

In most cars, there is still a cable that attaches to the butterfly in
the throttle body. Injector operation is controlled by the ECU based on
the airflow measured through the throttle body or manifold, and assorted
other sensors' input, rather than direct input from the pedal.

 

Actually, as I understand it, there is an electric pump to reduce the load
on the engine, there is still a mechanical connection between the front
wheels & steering wheel.....I could be wrong.

 

none of the above guys. drive by wire is simply having the throttle
operated by a computer controlled servo. it means there is no
mechanical connection to the pedal any more - just a sensor that acts as
input for the ecu, and the ecu uses that in conjunction with a bunch of
other info to calculate how wide to open the throttle. it's especially
advantageous for automatics as it means you can de-throttle when the
gear changes. injection really has nothing to do with it.

 

yes, electrically controlled power steering. that's not drive by wire.

 

it would not be "drive by WIRE" then.
for "drive by WIRE",the steering commands come through the wiring,not
through any mechanical linkage.

And by top posting,you destroy any logical continuity of the thread.

 

No,"DRIVE by wire" is electrically controlled STEERING.
You are describing "throttle by wire".

My 2003 Nissan Sentra SE-R SpecV has throttle by wire;the throttle plate is
controlled completely by the ECU. Because of some wierd problem,my RPMs
sometimes rev up to 1500-2000 RPM and hunt around there for a second,then
slowly drop back to idle,without my foot even on the gas pedal.It's caused
a CEL of "idle RPM too high".I either need a new PS pressure switch or new
programming of the ECU(according to a service bulletin),which can of course
only be done by Nissan dealers;....at some charge.

I might be able to get the reprograming done under a different safety
recall at no cost.

 

Drive by wire means that the linkages in a system are not all
mechanical. The system can be brakes, steering, throttle, etc.

http://en.wikipedia.org/wiki/Drive_by_wire

Jeff

 

I agree. In airplanes (that receive continuous maintenance) it's ok but
not in cars many of which are driven by idiots or worse.

Give me a mechanical link to the function of steering, throttle and
brakes anyday!

OTOH, the L1011 is a fly by wire plane with a perfect safety record.

JT

 

no such thing that i've ever seen on a civilian road vehicle. honda is
simply mechanical power steering [just like any other car] but with
electronic control on the degree of assist.

which is referred to, by honda and other manufacturers, as drive by wire.

 

not on its own it doesn't. throttle position is just one of many sensor
inputs that the ecu uses to calculate injection duration. these also
include:

oxygen sensor
coolant temperature
air temperature
air pressure - manifold
air pressure - atmosphere

throttle position is just part of the equation. if you want to check
out how the math is done, read this:
http://www.megamanual.com/v22manual/mfuel.htm

 

From Honda's website...
http://automobiles.honda.com/accord-sedan/features.aspx?Feature=drivebywire
Drive-by-WireT Throttle SystemInstead of a mechanical linkage from the
accelerator to the fuel-injection throttle, the Accord Sedan uses
Drive-by-Wire technology. The system uses an electronic position sensor
connected to the accelerator pedal that sends an electronic signal to the
Powertrain Control Module (PCM).

 

still have one.

why? all a throttle does is control air. with a diesel, "throttle"
doesn't even do that!

if you have hydraulic or air brakes, and most us have for at least 50
years, you have no direct mechanical linkage.

 

Hopefully, you have your answer but if not -

Drive by Wire typically refers to the electronic connection of the gas
pedal to the engine - so when you push down on the pedal, it sends a
signal to the engine control computer than you want to speed it. The
control computer then uses a whole series of inputs to determine how
to adjust the engine to meet your request. There isn't any mechanical
connection to the engine from the gas pedal. This is noticeable, for
example, when using cruise control - a DBW system won't cause the gas
pedal to move as the engine speed changes to maintain the cruise
setting. My Audi A4 has this feature.

Electric (or electronic) power steering simply replaces the hydraulic,
engine-driven power steering pump with an electric pump that doesn't
require being hooked to the engine. The steering is still a direct,
mechanical connection, so that if the pump fails, you can still steer
the car (albeit requiring much more force). I don't know that any cars
currently made have a non-direct mechanical connection between the
steering wheel and the front wheel, and would be VERY surprised to see
that happen in the near future.

Dan D
'07 Ody EX
Central NJ USA

 

wow, cheers guys, look like i started something there, didn't I? lol

Thanks again I now have a little more understanding

Thinking of buying a used 2.2 Diesel and noticed this wording and never seen
it mentioned before.

Does anyone have a 2.2 accord? Your comments on the vehicle i would
appreciate....

thanks again by the way...

AE

 

yes,and the L1011 gets constant maintenance and checks,and has triple
redundancy in the flight controls.

 

Actually, the L1011 has four separate hydraulic systems.

You bet they're maintained. Such doesn't exist in the automotive world.

JT