A worth while advancement in auto technology? Or maybe just a technology used to eliminate one more job at the the factory?
It eliminates a job at the factory. Obviously.
I don’t think it eliminates any factory jobs. I’m not in favor of anything complex on a car myself. I believe that the electronic throttle allows more precise control of engine fuel economy, and multiplied by 3 million cars or so that does a lot for the CAFE ratings, and helps avoid government penalties.
In summary, I think it’s a bad idea,. However,the number of manhours to build a car is steadily dropping, because of manufacturing efficiency improvements, so that YOU can afford more car for the same amount of money.
When Henry Ford first started building Model Ts they were quite expensive, and the average American could not afford one. When they reached their peak production the cost was down to $330 or so, and every American could aspire to own one. But the manhours per car had dropped siginificantly.
Scares the hell out of me.
I’m glad my cars still have throttle cables.
I’m betting this will become a big issue in the near future.
With the gas peddle hooked directly to the throttle by cable, the throttle position sensor reads the position, and the ECM must comply with your wishes giving the driver 100% control. Unlike electronic throttle control were the position sensor at the gas peddle is read by the ECM, and some goofball programmer at the factory determines the throttle position!
It can be used to lower emissions and make shifting seamless (with automatic transmissions). It’s complexity must cost MUCH more than a simple cable and return spring. Where Toyota got into trouble, they tried to fine-tune throttle “feel” with a friction device but instead created a monster…Now they are working 24/7 to eliminate the “friction” and the soft “feel” of the gas pedal…
I think a new standard for the friction device for a electronic gas peddle should have a built in break away device. So if the friction device locks up the break away device will still let the peddle return to idle (Like having two friction devises built within each other with the one being a fail safe. The Break away device will need a mechanical clicker device to worn the driver there is a problem with the gas peddle.
I bet the FMVSS 124 gas peddle standard will be revised in the near future.
Agree; it’s a good idea on large complex machines like airliners where direct control is impossible anyway. But something as simple as a throttle, 4 feet away, should be DIRECTLY controlled by your foot.
"I’m betting this will become a big issue in the near future"
hasn’t it already become a big issue, (with Toyota?)
Yes, aren’t ALL the throttles, in the news, Toyota electronic throttles?
As a safety measure, is there any reason why the brake pedal shouldn’t be wired to return the throttle plate to the idle position?
[ADDED later: The throttle plate would go to the idle position EVERY time the brake pedal was depressed. From a performance standpoint, is this acceptable?]
No! I read somewhere that brake override cost less then ONE DOLLAR per vehicle. I bet Toyota wish they spent the one dollar. However it wouldn’t have prevented a recall, but it would have prevented the big spectacle.
You think throttle-by-wire is scary? How about brake-by-wire? http://www.aa1car.com/library/2004/bf110412.htm
I don’t even like the fact that my AC kicks on by itself when I put the defrost on. Throttle by wire, steering by wire, braking by wire, all of these bother me. More and more control is being taken away from the driver and given to computers and microchips, much of it in the interest of squeezing more and more mileage out of the vehicles tiny bit by tiny bit. Even the lights are now controlled by “lighting control modules” that cost hundreds to replace.
It also bothers me that the braking systems are now being used for all sorts of other purposes such as stability control and even traction control. More complexity means more opportunity for problems, and many of these “improvements” come with tradeoffs. We’ve discussed the ABS tradeoffs at length in other threads.
IMHO critical safety systems such as brakes, steering, and even acceleration, should remain totally in control of the driver and as fault free as possible. Their function should not be subject to microchips or even the loss of engine power.
If a car is equipped with cruise control the throttle cable is both redundant and problematic, in assembly and operation. Eliminating the throttle cable is very cost effective. An entire a$$embly is omitted and the tedious ta$k of in$talling it also.
Scares the hell out of me. I’m glad my cars still have throttle cables.
I wonder what the overall real world failure rate really is for all types of controls and broken down by types, including carpet issues.
I am not at all sure (I have not seen any study) of the relative safety of the two systems.
On another issue, Is it not easier to gain more precise engine control using drive by wire?
We have yet had a braking system that was perfect. They all have some sort of safety issues. It would be an interesting study if someone was to do a really good study. I wonder what system would turn out to be the safest. It would also be interesting to know how much of a issue this really was compared to things like carpet issue, rusted brake lines etc.
The news media tends to focus on the extreme cases or the unusual. Since most all Toyota failures will be reported, I wonder what % of cases caused by carpet or mechanical failures like rusted lines?
I don’t see how throttle by wire (TBW) eliminates a factory job. I doubt any modern factory has a person doing nothing but installing throttle cables.
Throttle cables and linkages can hang open too. I found that out the first time I drove my “Weberized” '81 Accord long enough to get everything hot under the hood.
If I designed a brake override I would cut off the fuel injectors when the brake pedal is depressed and the engine is above ~1000RPM. No problem if the throttle plate won’t close.
I don’t mind TBW and other electronic approaches, if they’re designed conservatively with redundancy. Maybe I’m biased as an electrical engineer.
My '06 Matrix stickshift has TBW. One thing I notice is I can’t lug the engine, even if I try.
Wrong! The electronic throttle controls at both ends are far more expensive to build and install. But it DOES make the (now) all-important Cruise Control cheaper to build and install…It looks like they are more concerned about cruise control operation than anything else…As Hellokit pointed out, a simple brake to throttle override solves the problem. If there is a conflict between the gas pedal and the brake pedal, the brake pedal wins and a big, red warning light comes on…
What’s more expensive, C-man? The cruise servo operates the actual throttle as directed by applied voltage. The ECM can use input directly from the throttle to direct the throttle. A position senser is required for input into the cruise and shift control. Why have a redundant hard cable when all that is required is programming the ECM to always control the throttle, not just when in cruise?
some throttle cables do eventually wear out and can stick, but I have never had one that did. My son has a new Jeep Liberty with a “wireless Control Module”. That thing failed at 2700 miles. I think cables and wires are better.