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Toyota Problem Not Associated With Floor Mats

Has anyone identified the problem that would cause a Toyota to actually accelerate spontaneously? Floor mats cannot do that, can thye?

Someone might have let the floor mat get over the gas petal, but I thik the problem is with the "wireless throttle control.

EllyEllys, I think you meant cable-less throttle, not wireless, the throttle is not remote control, that would really suck!

One example I saw was the floor mat getting under the gas pedal, which causes the pedal to stay tilted forward. But that’s only one of the alleged problems.

The other, more serious problem may be caused by a faulty electronic throttle control.

The problem you may mean is when the pedal is pressed and becomes stuck, causing acceleration beyond the level desired by the driver. Toyota found that wear and moisture combine to make the pedal stick. They devised a fix (insert a metal shim) and are repairing vehicles now.

What has Toyota said about faulty electronic throttle controls (ETC)?

With an ETC, does that mean that there is no mechanical connection between the gas pedal and the “feed” for the fuel injectors?


How does the throttle work?


There is now an additional NHTSA investigation into unintended acceleration of certain Toyota models. This is not a case of the acclerator sticking in position when you remove your foot from the pedal, but rather the accelerator allegedly flooring itself. The Feds are focusing on the electronic “drive by wire” system for this particular problem, which makes this the 4th Toyota safety issue to arise in recent weeks/months.

  1. Floor mat issue
  2. Sticking accelerator (this is the one with new parts–shim + ??–being sent to dealerships)
  3. Unintended acceleration, supposedly from the drive-by-wire system
  4. Prius braking problems, apparently caused by a problem in the regenerative braking system

What is the shim supposed to do?

Folks, you just HAVE to read this!

“3) Unintended acceleration, supposedly from the drive-by-wire system”

Can you provide a credible source for this? I just did a web search of recent news related to Toyota and unintended acceleration, and didn’t find anything. I have read of people that thought they had a different unintended acceleration event than the other 3 well documented issues. I’m sure anything related to unintended acceleration will be flogged mightily in the months to come. I ask because there is enough panic surrounding the issue and Toyota owners don’t need rumors keeping them up at night. Judging by the reaction of several posters recently, three of the four problems you listed have a lot of people spooked.

Part of the floor mat problem is that people are installing them without the little hooks that are used to anchor the mats in place. If the little hooks AREN’T used the mats sometimes creep up and interfere with the pedal.

In designing any new system, such as throttle-by-wire, failure modes must be part of the design consideration, and usually are a part of. Did Toyota follow this principal? When you design, you design with the question, "What happens when the system fails? What are the fall-back provisions to be included in the design?"
Stuck throttles aren’t a new thing. They have occurred from the first throttle hundreds of years ago. Did Toyota NOT believe this could happen in THEIR design?
The article that eschamp2001 shows a link to, says that Toyota will be providing a brake over-ride on the 2010 Toyota. Good, but late.

The car wash people NEVER rehook the mats!

Car and Driver, March, 2010, did a test with a V-6 Camry, an Infinity G37 and a souped-up Mustang to see if the brakes could stop the car with the throttle stuck. It took only an additional 16 feet to stop the Camry from 70 MPH with a wide-open throttle than it did with the throttle closed. The Infiniti was even better because its system closes the throttle electronically when the brakes are applied. That’s what Toyota needs to do. BMW, Chrysler, Nissan/Infiniti, Porsche and VW/Audi already do this.

We are told: "Simply brake with 2 feet, put the car into neutral then turn the engine off."
MAY NOT BE SO SIMPLE! Watch these video clips:

(after putting car in neutral and unable to turn off engine!!!)



and the CA crash:
“911 Call Released from Crash that Prompted Initial Toyota/Lexus Floor Mat Recall”
(with California Highway Patrolman driving unable to stop vehicle)

"Witnesses saw flames coming from the front and rear tires of the speeding 2009 Lexus ES 350 before it crashed Aug. 28 in Santee, suggesting ?long, constant heavy braking,? said Sgt. Scott Hill, the lead sheriff’s investigator. "

"Toyota Recalls Spur Worries"

At this point, we almost need another forum dedicated solely to Toyota unintended acceleration. As an aside note, on my way to work yesterday, I was almost praying for any kind of acceleration from the Toyota minivan in front of me on the highway… lol

But I really think the problem is a bug in Toyota’s engine management software that only emerges in very rare conditions. Such as if on your computer, you were using an office program, then decided to do some odd combination like CTRL+ALT+F12, after copying data to the clipboard twice, then when you pasted the data, you got something entirely different. Only 1 in 100,000 people may perform this combination of actions, and it may not affect the software every single time—lets say only if your email was open at the same time.

This is only an example, but when you have several pieces of software that are interacting on some level with each other, in millions upon millions of lines of code, you can’t always test for every bug–it’s just impossible.

Now transplant that example to your Toyota. You’ve been cruising at 65 MPH exactly, the defrost is on, causing the AC to run. You’ve just tapped the brakes because someone almost cut you off. Let’s say the engine management system had decided that your extended 65 MPH cruise was a good time to open the EGR or do some other emissions-related event because you wouldn’t normally notice it at cruise speed, but the AC being on adds some unusual data to the program. Now you tap the brakes but still resume cruising… The emission control subroutine tries to stop the EGR event, but a software bug instead crashes that part of the program, and the data from the brake input or leftover from the EGR event gets put somewhere in memory it was never intended… in this case in the memory location or register that indicates the throttle position, overriding any input from the actual accelerator. Bingo! Your car takes off like it has a mind of its own! You could consider this a “cascade failure”, where no one event causes a problem, but unrelated events working randomly together can cause a catastrophe.

Eventually some “sanity” check in the software compares the throttle with the memory and decides they disagree. So the unintended acceleration event is now over. But due to an exception like this never being planned for, the computer doesn’t know it should write the erroneous event to a log or turn on the ‘check engine’ light.

A similar chain of events to my fictitious example is what I think Toyota will eventually find in examining their software. It may be that similar oddities exist in other manufacturers’ software, but they have one more level of sanity checking (like BMW, Chrysler, Nissan, etc. overriding the throttle when you hit the brake) or just whatever bugs they have end up causing something mildly weird, like your engine fan to run for a few seconds, not potentially dangerous like unintended acceleration.

I think that in the end there’ll turn out to be more than one root cause. Floormats may indeed be one of them.

More and more people are coming around to Oblivion’s theory. My own gut suggests that they’ll find the common cause to be the transducer in the throttle assembly. I have zero data to back me on this, it’s just a gut feeling. They’ve probably tested the ECUs in every way possible by now and seem to have determined that it’s the input signal that’s at fault. They’re currently blaming the design of the friction system that’s integrated into the assembly to provide proper pedal feel. I’m not “buying” that theory. My guess is that the only way to correct the transducer is to replace the entire pedal assembly and they’re avoiding doing this for two reasons: (1) cost, and (2) they haven’t fully qualified and validated a design change yet. That testing takes time.

My money is on the transducer. If I win, I expect free corn muffins. If I lose, it’s free corn muffins for everyone.

If this is the case, actually hitting the gas pedal a couple of times might fix the problem, counter intuitive as it may be.