electronic throttle?

On Sun, 21 Nov 2004 03:43:59 GMT, "Bill Jones" >
wrote:

>The December issue of Road & Track has a great review on the '05 Mustang GT.
>
>http://www.roadandtrack.com/article....rticle_id=1662
>
>
>In it, the reviewer says,
>
>"Response for the first few hundred rpm off idle is soft, the result of only
>281 cubic inches, two tons of all-up weight and what must be conservative
>engine management. And while we're griping, electronic throttles are the
>work of the financial devil, although we'll admit the Mustang's is the best
>yet. Tuners will have a field day providing crisper off-idle and
>snap-throttle operations via computer reflashes and 3.73 gear sets. The
>burnout crowd will not see any progress in losing the throttle cable either.
>For the rest of us, the smooth 3-valve makes more power, fewer emissions,
>gets the same mileage and lives on 87-octane gasoline."
>
>So, what is electronic throttle? There's no cable from the gas pedal to the
>engine? Does it really result in softer response at low rpms?

yup, no cable. There's sensor at the the pedal which measures the
position of the throttle, and there's some sort of servo at the intake
that is controlled by the computer, using the input from your pedal.
Fly/drive by wire, used in almost all new commercial airlines after
airbus started using it.
Now, I have driven a bmw 3 series and I think they have this system
already. Like other people have commented on, slowly accelerating from
a light is harder than on 'wired' cars. Not sure why, it's almost like
a slight delay, then it takes off.

Remove NO-SPAM from email address when replying

Hey Jim,
Does the throttle by wire allow Ford to ditch the Idle Air Control actuator
or speed control servo unit and hardware?

"JS" > wrote in message news:5y4od.4535$hJ6.472@trndny01...
>
> "John" > wrote in message
> ...
>>
>> It sounds like a computer conditioned servo-mechanical circuit. The
>> airline industry has used these for years for many reasons like lower
>> weight than all those cables, facilitate autopilot, record flight
>> commands, and maintenance is concentrated in just several places (the
>> sender, the computer, and the receiver) and not the entire length of the
>> cable. Some folks think it'll eventually lead to eliminating the
>> co-pilot and later possibly the pilot. I have a friend that pilots the
>> big ones on the Europe/US routes, and he says there is *not* a single,
>> traditional mechanical cable in it now. Everything goes thru the
>> computer.
>
> I can see on an airplane or something where there are probably miles of
> hard cable, but we're talking a couple foot piece of low-tension cable.
> On the plane, it would be lower weight, easier to assemble, and perhaps
> cheaper on the plane, depending on how much it costs to wire it and if
> it's a bussed system or single wire per servo. On the car, it adds ease
> of assembly and the possibility to locate the throttle body anywhere on
> the car (helps the ram-air systems I guess) without the unsightly cable,
> but I doubt it'd be much cheaper. Yes, the cruise control already
> operates under the same idea, but the CC servo can't be remotely capable
> of what the throttle servo would need to do - a nearly instantaneous
> opening of the throttle just isn't in the typical CC servo's operation
> capability. When was the last time your cruise baked the tires off?
> (note that this isn't a shot against you, just a general rant about the
> system)
>

I don't know, it seems very likely to me that one servo could do the job of
both the cruise and throttle function. Granted, the servo at the throttle
body would have to meet the most demanding requirements, i.e. the throttle
function, but if it could do that doing the cruise part should be a piece of
cake. I'd bet they are separate functions or subroutines or phases in the
computers program though. DriveSpy posed the question of one servo below.
Hopefully someone really knows.


>> You have to admit it consolidates components for the cruise control real
>> nice.
>
> That it does....
>
>> I wonder how long throttle commands are stored in the computer and if the
>> police will ever use it?
>
> Throttle commands are most likely stored to allow the computer to better
> respond to the driver and anticipate the next move. I don't know if the
> police will use it... speed logging would be more beneficial than
> throttle. There's times you need to floor it... highway onramps, etc. I'm
> sure they could already pull a speed log if they really wanted to.

You are right on speed logging, I was thinking post-accident investigation.

--
John
ThunderSnake #59
If you Reply, be sure and remove the " (DELETE_THIS) " from the email
address.

Oh, man..... I can imagine what that must be like to work on. I can't
imagine what it must cost to fix it off warranty...

Taken from the 2005 Ford PC/ED manual...... there are two "styles" of
electronic throttle bodies (no mention is made of which goes to which
application) but the difference is in whether the servo-motor is part of the
throttle body or attached separately. The TPS is redundant... one part is
negative slope and the other positive slope. The throttle pedal assembly is
triple redundant..... one negative slope sensor and two positve slope
sensors - the two positive slope sensors share VREF and GND circuits but
have separate SIG-RTNs. No mention is made of an Idle Validation Switch as
found on the diesels (which have been drive by wire for many years, though
they have no throtle plate). There is no IAC and cruise control functions
are through the PCM. During failsafe operation, vehicle speed will be
limited to about 48 mph.

AFAIK, sensor readings are not stored in the PCM... they are simply live
data - read - reacted to and discarded. The restraints control module is
(again AFAIK) still the only place where crash data is stored and it takes a
significant event to initiate the data storage sequence.

Yes... see my reply to John for some more info....


"DriveSpy" > wrote in message
...
> Hey Jim,
> Does the throttle by wire allow Ford to ditch the Idle Air Control
> actuator
> or speed control servo unit and hardware?

"John" > wrote in message
...
> "JS" > wrote in message news:5y4od.4535$hJ6.472@trndny01...
>>
>> "John" > wrote in message
>> ...
>>>
>>> It sounds like a computer conditioned servo-mechanical circuit. The
>>> airline industry has used these for years for many reasons like lower
>>> weight than all those cables, facilitate autopilot, record flight
>>> commands, and maintenance is concentrated in just several places (the
>>> sender, the computer, and the receiver) and not the entire length of the
>>> cable. Some folks think it'll eventually lead to eliminating the
>>> co-pilot and later possibly the pilot. I have a friend that pilots the
>>> big ones on the Europe/US routes, and he says there is *not* a single,
>>> traditional mechanical cable in it now. Everything goes thru the
>>> computer.
>>
>> I can see on an airplane or something where there are probably miles of
>> hard cable, but we're talking a couple foot piece of low-tension cable.
>> On the plane, it would be lower weight, easier to assemble, and perhaps
>> cheaper on the plane, depending on how much it costs to wire it and if
>> it's a bussed system or single wire per servo. On the car, it adds ease
>> of assembly and the possibility to locate the throttle body anywhere on
>> the car (helps the ram-air systems I guess) without the unsightly cable,
>> but I doubt it'd be much cheaper. Yes, the cruise control already
>> operates under the same idea, but the CC servo can't be remotely capable
>> of what the throttle servo would need to do - a nearly instantaneous
>> opening of the throttle just isn't in the typical CC servo's operation
>> capability. When was the last time your cruise baked the tires off?
>> (note that this isn't a shot against you, just a general rant about the
>> system)
>>
>
> I don't know, it seems very likely to me that one servo could do the job
> of both the cruise and throttle function. Granted, the servo at the
> throttle body would have to meet the most demanding requirements, i.e. the
> throttle function, but if it could do that doing the cruise part should be
> a piece of cake. I'd bet they are separate functions or subroutines or
> phases in the computers program though. DriveSpy posed the question of
> one servo below. Hopefully someone really knows.

I'm sure that there is only one servo now... would seem senseless to have
two fighting each other. I was just mentioning that the original servos
that ran the cruise couldn't have dealt with this kind of use/abuse on a
regular basis. The CC servo lives a pretty easy life comparatively
speaking.

>>> You have to admit it consolidates components for the cruise control real
>>> nice.
>>
>> That it does....
>>
>>> I wonder how long throttle commands are stored in the computer and if
>>> the police will ever use it?
>>
>> Throttle commands are most likely stored to allow the computer to better
>> respond to the driver and anticipate the next move. I don't know if the
>> police will use it... speed logging would be more beneficial than
>> throttle. There's times you need to floor it... highway onramps, etc.
>> I'm sure they could already pull a speed log if they really wanted to.
>
> You are right on speed logging, I was thinking post-accident
> investigation.

Good point. I'm sure they *could* do it... it's just a matter of if they do
it or not.

JS

> --
> John
> ThunderSnake #59
> If you Reply, be sure and remove the " (DELETE_THIS) " from the email
> address.
>
>
>

"JS" > wrote in message news:1cfod.7965$sX5.3794@trndny05...
>
> I'm sure that there is only one servo now... would seem senseless to have
> two fighting each other. I was just mentioning that the original servos
> that ran the cruise couldn't have dealt with this kind of use/abuse on a
> regular basis. The CC servo lives a pretty easy life comparatively
> speaking.
>

Agreed.

--
John
ThunderSnake #59
If you Reply, be sure and remove the " (DELETE_THIS) " from the email
address.