Why the "Out of Control" Prius Driver Is Full of It

I'm wondering...at full acceleration, using both ICE and electric motor, how long until the battery is depleted and you're running on ICE only? In my experience (on my 2005 Prius), when the battery is low, the ICE provides very, very weak acceleration. So...is it reasonable to think the battery would support uncontrollable acceleration for 20 minutes? You'd have to be getting a pretty efficient recharge of the battery via the regenerative braking system.

 

I agree that we need to keep open minds and not discount the possibility of real technical problems.

Much of the criticism leveled at the drivers comes not from them saying they had a runaway situation, but from the inadequate attempts at stopping the runaway cars.

Cars will fail. Every system can and will fail in mysterious and unexpected ways. This is a fact of life that all of us engineers live with on a daily basis. I recall a wise senior scientist that referred to this as "The cussedness of things inanimate." I like that description. As drivers, we need to know how to deal with emergency situations. Sadly, many drivers are woefully unprepared.

Technical failures lead to crashes. Each event needs to be analyzed to see if anything can be learned. In reality, though, most crashes are caused by pilot error. Even the best safety systems are often inadvertently sabotaged by human failure. It is because of this that we often first look to driver error as an explanation, especially when the circumstances are suspicious.

Should we assume that all failures are driver induced? No. Neither should we automatically assume that all failures are real failures.

Tom

 

Darn it all...this was suppose to be quoted from a previous comment. Now it sits here out of context:

Exactly... Press on brake and hold, then press on accellerator equals Nothing! The brake assist is working as it should. But in the case of the runaway stuck accelerator my "jump to a conclusion" answer is that brake assist fails and the brake system has to override the continuing engine and traction motor torque to a safe stop and at very high speeds (70 mph plus?) with improper brake application causing hot glazed discs it can't do that well at all. My "real" answer is how the heck do I know for certain. I don't know the driver and I don't know the brake failure design modes tested.

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I'll add though that I'm totally with what Tom said. And then add:

There are two different 'trends' that have been set up here. The fact that there seem to be more and more runaway Priuses now tends to lead me to think there is an underlying mechanical problem (for speculation only, in the ECU where ICE, Traction Motor, Brake Assist, and acceleration/deceleration all come together). The second 'trend' is driver error--improper application of the brakes ruining their effectiveness?; not knowing how to go into Neutral and what the real results to expect will be?; not knowing how to "Power" button 'off' the car and what the real results of doing that would be?

 

I think he meant starting from rest (as in the case of stopping on an incline), not while moving at highway speed. Makes perfect sense to me.

 

Honestly, I did not really know if it would work while at highway speeds. I actually thought it would not override at the accellerator at highway speeds, but I guess I am wrong.

 

That barefoot test does not tell us just how good the Prius brakes are in real world conditions under prolonged braking.

Sorry.

 

Just a reminder to all. The Prius "power brakes" still work even if you turn the car off. Those of you who actually -own- a Prius will know because the brake booster fires off when you press the brake pedal to turn the car on. So the car doesn't have to be on for it to work.

 

Does that mean the "power brakes" are electrically driven on the Prius instead of engine vacuum driven ?

Interesting.

 

Someone else posted that there is no booster.... So, wassup???? Either there is or is not a booster. Folks, we need to get our stories straight. It goes to credibility.

 

that's good

I'm torn on this story. Interested to know exactly what happened with the brakes and how they were burned up. Maybe he was stomping the accelerator and brake or something happened with the cruise control.
On the other hand I can't understand not putting in neutral. He may have been panicked but according to the interviews he had time to evaluate all his options and incorrectly decided the logical ones would be unsafe. Much safer to try and reach down and grab the accelerator while speeding out of control. Only after CHP arrived did he try one of the options common sense would say to try. I think the Prius would be one of the easier cars to put in neutral in a panic. Just move it to the left for a few seconds - no worry about going into a different gear. Even simpler is hitting the park button. For those saying he's a liar because of body language - maybe. He could be embarrased for not trying anything common sense would dictate.

 

Personally, I wouldn't encourage anyone else to experiment with their vehicles on the public highways.

You must be joking right ?

I repeat, do not test your vehicles on PUBLIC HIGHWAYS.
If something does go wrong, someone else could pay for your mistake.

 

That's true about Power Brakes but Brake Assist is different. Brake Assist is what causes the ICE and Traction Motor to drop to idle when the brake is applied under any condition. I believe it is the same switch at the brake pedal that disconnects Cruise Control too. Come to think of it CC needs to be added into the 'big picture' too.

 

No, they are quite serious. It is a manifestation of arrogance. That is how you can become safety deaf - by drinking your own Kool-Aid. Do the test on public highways. The car is safe because I said it was safe.

Got the picture?

 

Some part of the car is always on, even when you turn it off, unless you cut or disconnect the right wire to kill it. Trying to kill it, but not doing it will only piss it off. One of the prii brethren in england has already tasted human blood. I don't know if toyota has transfered the taste of blood to the other prii during maintenance periods yet, but I am afraid.

Back to reality, I don't think its right to call it a typical booster. The whole braking thing has electronics all through it. The pedal pushes fluid, and this stroke is read electronically and stuff is done. We don't know exactly what stuff, but part of the braking brain of the prius (BBP my term) decides whether to apply regenerative and/or friction braking and actuates this electronically. This is what happens in all normal circumstances so electronic systems actuate the friction brakes. If the BBP is dead, we can hope that a solenoid allows a strictly mechanical system to take its place (Don't think we have reports of this failing). This mechanical system does not have electronic or vacuum assist. The BBP is reported to tell a run away throttle to go away. We don't know all the conditions for this, but if there is not a hoax there was a problem in this hardware and/or software in the san diago case. There was not an allegation that there was a problem in shifting to neutral.

 

It isn't paranoia. It is prudent caution. And I'm leaving this thread now because it is uncontrollably out of balance weighing on the side of attacking the drivers involved. I'll also report your post but doubt a moderator will close the thread. But heck, there are so many other threads.

 

Have a little common sense. Don't try a brake test on a busy road. Don't do anything foolish. Go find some empty road and learn the finer points of controlling your Prius. If you have access to a closed track, so much the better, but it's not like we are talking about anything dangerous or even scary.

Tom

 

From what I understand of the Prius, there is no switch per se. Instead both the brake and accelerator pedals hook straight to the computer and the computer decides what to do. But the brake pedal is physically connected to the hydraulics of the brakes system. So with no power, depressing the brake pedal will cause the brakes to activate. But with the computer's assist, power brakes can apply more braking force than is normally possible from pure mechanical action from the driver. The cruise control and starting system using the electronic information for their needs, but it comes from the same sensor.

The gas pedal on the other hand only goes to the computer. The computer decides how much to accelarate and with what. Now in this socal incident, the computer could have had a glitch that said go! But the driver riding on the brakes would have only engaged the mechanical portion since the power brakes are off, since the computer thinks it should be accelarating. Could this result in the brakes not engaging fully? Probably not, since the power brakes don't really lower braking force. But then the anti-lock brakes do just that...

But what remains is why didn't he just shift to neutral? Well reports seem to indicate the driver was worried about flipping the car, hmmm... Suspicious yes...

 

In science there is the concept of poisening the pot. A person latches on to an idea. Others on the team reainforce this. Then the entire teams ego becomes involved, poisoning any logical analysis. Whenever evidence comes up, it is quickly discounted because the mind is already poisoned.

Let's take the facts at face value. The car accellerated, the brakes did not kill the throttle, the driver latched onto the wrong idea that shifting to neutral at high speeds might flip the car. Each time he was asked he had trouble with this question. Maybe the first time he thought this but when asked all he could think of was this scenario. Ofcourse there are other possible explanations.

Now lets go to the forum members. Before any facts came out, people were shouting fraud and driving error. First it was get out of a speeding ticket, then when that looked wrong, to get out of a ticket for using a cell phone, to sue toyota, etc. It must be a hoax right? This reasoning may be coming from a more poisoned pot. It can't be toyota so it must be a conspiracy.

Now there is a possibility that neutral will flip a car, or that all driver reports are hoaxes, but I hope those forum members still with good minds will look at evidence and not keep repeating - "neutral will flip the car", "gm rigged this", "the media is in a witch hunt", "the driver set up a hoax".

 

fwiw, the bankruptcy of James A Sikes is confirmed:

Filing Number: 3:08-BK-05026
U.S. BANKRUPTCY COURT SOUTHERN DISTRICT OF CALIFORNIA (SAN DIEGO)
Filing Date: 06/05/2008

His latest venture is a new corporation organized in California called Adultswinglife, LLC. See Business Search - Business Entities - Business Programs

Entity Name:ADULTSWINGLIFE, LLC
Entity Number:200907910219
Date Filed:03/19/2009
Status:ACTIVE
Jurisdiction:CALIFORNIA
Agent for Service of Process:JAMES A SIKES
Agent City, State, Zip:CARLSBAD CA 92009

 

Brake Assist is a feature to reduce reaction time in a panic stop. The Prius monitors brake application speed as well as brake force. If the Prius detects that the driver rapidly moves from the accelerator to the brake and rapidly presses the brake, the Prius assumes this is a panic stop and activates full braking force even before the brake pedal is fully depressed, thereby reducing braking reaction time.

Tom