Toyota Recall 2
Toyota Recall 2
(OP)
I have read the previous question involving the Toyota recall and there was more things i was wondering about this incident. There is alot of talk about a "drive by wire" system.How does this system work? I also heard that Audi had the same problem about 20 years ago. What happened in that situation? Thank you for answering.





RE: Toyota Recall 2
Since the driver does not mechanically control the throttle, there is a feeling among some that a final driver veto on the system is missing. However, given that mechanical linkages can break (and more often than electronics), there is a feeling among others that drive-by-wire is just as safe, although it does depend on having a good design in the electronics and software.
Don't know which Audi thing you're talking about, so I'll leave that part to others.
RE: Toyota Recall 2
The throttles and transmissions of the cars in question are controlled "by wire". No direct mechanical connection from the pedal or gear shift lever to anything.
To some of us oldtimers, that brings the electronics into question...especially everytime I must reboot this PC...
I really like direct control over my vehicle. Since most of my vehicles are either classics or antiques, that's not a problem. The wife's Lincoln is all DBW and, after nine years and 170k miles it has not been a problem. Perhaps I really am TOO old.
One thing mentioned...broken mechanical linkage. Hmmmm. In well over 50 years of driving, street and race, I've had ONE throttle failure and that was in the early 80's in a race car...the throttle cable came out of it's "detent"...My fault since I built it wrong.
Rod
RE: Toyota Recall 2
The story, as related to me, was that people would rest their foot on the throttle pedal thinking it was the brake. Then, they'd shift into gear, and the car would start moving. Then they'd push the "brake" harder. Voom!
RE: Toyota Recall 2
Also, maybe the auto designers should have a look at how Yamaha did the drive-by-wire throttles on the current and prior R6 motorcycle. The computer takes an input from a sensor and positions the throttle, but there is also a mechanical linkage from the rider's throttle to the actual throttle mechanism at the engine. The computer is capable of opening the throttles *up to* the amount that the rider requests, but never more. That way, if the rider closes the throttle, the throttle closes, no matter what the computer thinks.
Presumably, full electronic control was not considered to be fail-safe enough for a motorcycle with 100-plus horsepower weighing less than 400 lbs.
RE: Toyota Recall 2
I've really only played with the stepper motor idle control valves and they wouldn't react this same way since they really can't move faster than their operating speed. Also, a sticking stepper type typically just won't turn anymore. The electronics can't apply a stronger signal until they break it loose.
Detailed info on the internet is hard to find for the Audi case and I didn't come across anything with enough detail to fully describe what was going on with the idle controllers.
RE: Toyota Recall 2
RE: Toyota Recall 2
RE: Toyota Recall 2
RE: Toyota Recall 2
As regards the old Audi deal...That scandal left us with three things. One, it issued in the era of the "recall". Two, it brought us the brake pedal override so you cannot shift into drive without pedal pressure. Three, it has created an "industry" of attorneys that exist solely for the purpose of making said "idiots" rich.
For standard shift cars, they got the stupid switch so you had to depress the clutch pedal to start. It was such a good idea that the auto industry abandoned that idea in the late 30's (E.g., 1937 Nash Ambassador with starter button under the clutch pedal and activated by the depressed pedal).
Shucks, I must be crazy to ride my '48 Norton without a little green light to tell me when it is in neutral!!!
Rod
RE: Toyota Recall 2
RE: Toyota Recall 2
RE: Toyota Recall 2
The Audi idle control valves of 20 years ago did not actuate the throttle valve, only a small idle air bypass circuit. Wide open on that circuit the engine could not have made more than about 15 HP, if that. Sure, it could have slowly increased the vehicle speed but not cause it to leap from a standing start through block walls like some people tried to claim.
When you have just run some one over or had some other tragic accident, the mind refuses to believe it could be your fault and will come up with all manner of impossible excuses for what happened.
RE: Toyota Recall 2
Fully open can move a lot of air relative to a regular idle control motor, but it's still not going to be anywhere near enough to overpower the brakes.
RE: Toyota Recall 2
RE: Toyota Recall 2
If it's anything like the GM systems I've played with then I'd bet it'd produce the same results as what is required to run the engine >3000rpm in neutral. I'd think you'd be really concerned for your engine if a GM idle control valve stuck wide open. Even at about 30% it would be running the engine around 2500rpm.
Does anyone have the details on how the Audi idle controller motor is built and controlled?
We all know Audi would not come out and openly make a big deal about it being the problem, but they issued a safety recall for the thing as part of the solution to the sudden acceleration issue so Audi must have figured it was partly to blame.
RE: Toyota Recall 2
Yes, a joke. As far as the Fail WOT, it was thirty years ago that this happened, and my memory isn't what it used to be, but, I was somewhat conversant with control systms and remember thinkng to myself that it was an odd way to work it. Beetles had all sorts of interesting ideas, among them, gas (petrol) auxilliary heaters, using the spare to provide pressure for the window washer, the battery under the back seat, which would occasionally short out, etc. I could be, and, too often am, wrong though.
My main point is that mechanical systems are not fool proof either.
RE: Toyota Recall 2
Truth. ALL mechanical and electronic control systems CAN and, often do, fail. With the old cable throttle failure was generally to the idle position. When you selected "N" in the trans, you GOT neutral. Point is, yes, mechanical systems CAN FAIL but, in light of over 100 years of history, not as often as the new computer controlled system. At least that's the way it seems with a "zillion" more cars on the road.
I'm not your regular car guy. I'm an old racer. With most newer cars I don't get to choose, but I do not like Trac control, ABS, DBW, SBW, I'm not too crazy about automatic transmissions. My wife's car has all these things and more...therefore, I DON'T GET A CHOICE! If you get my drift.
Rod
RE: Toyota Recall 2
There is a funny video with some foul language on YouFool, I mean YouTube... where a guy in a ski mask for obvious reasons, shows that if you shift the Prius into neutral it rolls to a stop. He also shows that shuting off the ignition amazingly stops the car. Basically as a Prius owner he tales offense at people of questionable driving skills making other Toyota owners look like incompetent idiots. His point however about the Prius being fully controllable by the driver even if there were sudden acceleration is valid.
Warning -- Don't play the video if you're offended by blue language!
http://www
RE: Toyota Recall 2
RE: Toyota Recall 2
Wasn't the whole point about slowing the car to a stop?
RE: Toyota Recall 2
Audi also installed vacuum pumps to ensure that the brake booster absolutely, positively never lost vacuum. And then, they went to hydraulic brake assist.
As far as control is concerned, it works on the same principle as the Ford units.
RE: Toyota Recall 2
Not the end of the world, but you the consumer ended up paying 10-50 bucks per car for that.
Cheers
Greg Locock
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RE: Toyota Recall 2
Rod
RE: Toyota Recall 2
RE: Toyota Recall 2
You cannot cure human ignorance through technology. I have known people who were not aware that you could manually unlock a door in a power lock equipped car.
RE: Toyota Recall 2
RE: Toyota Recall 2
RE: Toyota Recall 2
jettisoning the batteries might work, but you'd also have to add an indicator light or flashing (up/down) arrow to show whether it was satan or the lord who had control... wouldn't want to inadvertently interrupt a miracle.
RE: Toyota Recall 2
Pressing brake and throttle together does not cut the throttle, or at least not for several seconds - I'll have to do some more trials to see if anything happens if you persist. As the car is manual with a conventional ignition key, stopping shouldn't be an issue in any case.
Nick
RE: Toyota Recall 2
Rod
RE: Toyota Recall 2
Here's the odd thing; despite the accelerator/brake interlock, VW/Audi are not excluded from "sudden acceleration" reports to NHTSA. It still happens to them. Operator error ...
RE: Toyota Recall 2
RE: Toyota Recall 2
The Volvo did have a mechanical throttle link (cable actuated).
I believe Ford recently did a study on their high performance Mustang and found that they could control it as well, and the Mustang has several times the wheel horsepower as the Camry or Prius.
Franz
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RE: Toyota Recall 2
There appears to be nothing wrong with the vehicle and the brakes were not burned out and function fine. You would expect the brakes to be burned up if the driver was actually trying to stop over the long distance that he traveled.
It's impossible to prove the incident was staged, isn't it?
RE: Toyota Recall 2
Heard the 911 operator several times suggesting knocking trans into neutral.
He says "I'm trying to control the car" (while talking on a cell phone)
This has 'balloon boy' part 2 all over it.
Neighbors and friends (?) say he's a grifter & BS artist.
RE: Toyota Recall 2
RE: Toyota Recall 2
RE: Toyota Recall 2
Rod