Cruise Control Switches to Runaway Mode

ConsumerAffairs.com has been noted by others as being very biased against the Prius. They are a front site for a legal firm.

Now, there is nothing wrong with expressing negative views about the Prius, and there is nothing wrong with product liability lawsuits per se, but these guys have exhibited some very bad journalism in their articles, seldom (if ever) attempting to verify information or obtain statements from the other side of an issue.

There is nothing in the article that would make me conclude that the cruise control or the hybrid control system was to blame.

Runaway conditions (stuck throttle) happen on all kinds of cars. It can be caused by a badly lubricated throttle cable, a cable that has been pinched or improperly fastened (this has happened to me, but not on a Prius), and as someone else on PriusChat has mentioned, a floor mat jammed up against the pedal could be the culprit.

The only interesting thing in the article is that it is claimed that someone at the service center initially duplicated the phenomenon. I'd like to hear a quote from that person directly.

- Bob R.

 

This happened to me, right after I got the car. New aftermarket deep rubber floormats. Scared me bigtime.

Joel

 

I'm not picking on you, Joel. Accidents happen.

 

I was in Linear Circuit Analysis II two years ago and the professor (Ramond DeCarlo, Purdue U.) told a similar story:

He told a story about when he was driving on the freeway, and cruse control manfunctioned. Aparently, the cruse control was an unstable sustem with the poles on the right side of a pole-zero plot of the transfer function. Thus the car continued to acelerate, and could not be shut off. He had to wait for a strait stretch of freeway and turn off the car. So he lost power steering, insterments, etc. switche to nutural and restart the car.

 

Bill -

I think Joel was definitely referring to just the floor mat issue, not the cruise control, because he was quoting just that sentence from my reply.

JMann -

What car was your professor describing? Given the inflammatory nature of the original "ConsumerAffairs" article, we should be careful to avoid potential misunderstandings.

- Bob R.

 

I think so too, BobR1, but I just asked for confirmation. My inflamatory remarks, You can get killed in your Prius if you stop in front of a fast moving locomotive, or leave the road and go over a cliff. It could happen to you... were meant to match the tone of the article. Please note my aside to Joel at the end of my post.

 

This is such an urban legend told to engineers I had the same story told in Sweden by my prof.! I highly doubt it's true. Also if it happens simply put the car in 'N' and use your brakes so why kill the engine?

/Robert

 

Does anyone know the law firm that is associated with this site? When I read the article it looked like the writer flunked journalism 101. Poorly written. Sounded like a 12 or 13 yr old wrote it.

 

No, yeah it wasn't my cruise control, it was the floor mat.

my last car, which I was very happy with and my mother is now driving, was a '95 Suzuki Sidekick. Shortly after I bought it I had aftermarket cruise control installed at a local stereo shop. They did a fine job, and I was the only person I knew with a manual tranny and cruise. But if I forgot I was in cruise (I only did this in the beginning) and put my foot on the clutch for whatever reason, the engine would begin racing as the cruise control tried to bring the vehicle speed back up. Now back to the post: if the cruise system were to malfunction, it wouldn't surprise me if putting the shift in N would leave cruise engaged, and the engine would start revving up. That would make me turn off the engine...

 

Sure, the engine would rev trying to match speed but still YOUR CAR WOULDN'T GAIN SPEED so you wouldn't have anything to fear (more then the engine malfunctioning). I would probably put it in 'N' make sure I could find a good place to stop, and then once stopped turn the engine off. I'm sure it's not good for the engine to rev but I would mainly be concerned with my own health. I don't particulary like being in a car that is not functioning.

Now turning the power off would leave you w.o. assisted breaks or steering making it very hard to panicv stop the car or swerve would something happen. So I would say, leave the car running until you have come to a stop. At least for a normal car, for a prius you could maybe kill the engine (somehow) and still have electric brakes and steering

 

I wouldn't be suprised if this article was based on truth but then exagerated. But the problem has nothing to do with the car being a prius. It was the cruise control that malfunctioned from what I read. Most cars have cruise control these days.

About a year ago one of my coworkers had a similar thing happen to him on his way into work. He was driving along and all of a sudden he felt the gas pedal depress on its own. Terrifying I'm sure, but he put it in neutral and restarted the car after he stopped. There were no mats causing the problem and it recurred a few times over the next month or two that he still owned the car. When he finally brought it in the mechanic wanted to replace some part of the cruise control. I don't know the details and I think that was when he got rid of that van. I think that particular van was a dodge, but I'm not sure and it was quite old and had a lot of miles on it, so I would never point to it as a problem with any specific car type. Its just one of many many things that can go wrong with just about any car. But in most cases it doesn't.

 

I believe the law firm is Horwitz, Horwitz, and Associates, Ltd. as reported by IsrAmeriPrius. There are several other musings about our "friends" at ConsumerAffairs.com in the threads mentioned below:

http://priuschat.com/index.php?showtopic=12768

http://priuschat.com/index.php?showtopic=12593

 

http://priuschat.com/index.php?showtopic=14596&hl=wild+ride

 

If a cruise control fails the first thing to do is just switch it off. That is a mechanical switch that should disable it unless the car has everything at once simultaneously failing. Shouldn't matter if the poles of the servo are stable or not.

 

I have become less prone, over time, to make "knee-jerk" conclusions like "liar", etc. These are computer controled cars and my computers have done some bizarre things. I also am not educated enough about fail sages. So, I use some other experiences and training to make general observations.

If Toyota has made 'fail safes" and tested them rigorously...then I will say my skepticism reigns high. I also know, when people get surprised, frightened, stressed, they lose logical thought.

Example, get into your car, start it up, and push on the gas to back up. NOW, if you, for some reason, had it in drive and you are suddenly jumping a curb heading for a pedestrian...there is a HIGH likelihood you will jam on the gas even harder and SWEAR you were hitting the brakes and they failed.

I have also investigated a crash where the driver swore his brakes failed yet i observed over 100 ft of skid marks. This driver just could not believe he couldn't stop before hitting the child (THAT is traumatic)

We can calmly state that pushing the power button or park would have solved the problem...but when sh*t is happening, you do not think clearly. You will then revert to what has worked in the past or just "panic".

Either way, when things are done and you try to calmly reconstruct the events...it is very hard to do.

I speak from training and experience in this. Our PD videotapes officers using simunlated ammunition in gun fights. It is amazing what is done vs what is remembered when you are being shot at.

I believe the premise of the story that the car suddenly accelerated (this happens to "notmal" cars...what I am skeptical about is ALL the factors that contributed or were tried.

Lastly, what does the owner/article write WANT toota to do...they couldn't find a problem. Ahhhh, maybe he wants a FREE new car or a refund.

 

Thank you for posting this smy I would not have seen it otherwise because I don't normally surf the web looking for Prius stuff. The general tone of the article reminds me of the really crazy stuff I've seen on some of the political web sites, on both sides of the spectrum. Anyone who is informed and objective won't pay much attention; but those who are looking for reasons to support a bad conclusion will jump on it and site it as "evidence".

If this actually happens to anyone their first reaction will be to push on the brake as friend Herbert claims to have done, and if nothing happens they will then push harder, and the car will stop. The brakes on any street legal car are far more powerful than the engine. If you push hard on the brakes the car will stop and it doesn't make any difference what the throttle or the cruise control are doing. If the throttle is really opened up you will need to push harder than normal but the car will stop. This is true of the Prius and it's true of cars with 3 or 4 times the power of the Prius.

 

Tumbleweed, it is my understanding that braking is not direct. It is computer controlled, therefore, this is not necessarily true.

 

the one thing that really stands out to me.

and i believe it is computer assisted, if you push it far enough, there is the regular hydraulic system there. someone verify this?