Sudden Acceleration - It Happened To Us Today

Thank you, Beshara1111. I am very aware of the "momentary surge" you're referring to. What happened to me (some years ago) was not at all a momentary surge. It caused me to fly across a curb and a raised sidewalk. Fortunately since Toyota replaced the accelerator (and I suspect they fixed more than that), I have not had a repeat. Thank you again.

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I've experienced this momentary battery surge when going over small bumps even if my foot is NOT lightly on the brake, and wondered if this can be fixed. My battery also make a quite loud (to me) buzz sound when braking or accelerating. Is this normal? And my car, which I just got, a 2008 package 3 with 67,000 miles, doesn't ever seem to want to be in stealth mode, except when stopped. Is this normal? I'd LOVE to drive at very low speeds with ONLY the battery!!!! THANK YOU![/QUOTE]

 

If you are "coasting" you are actually regen braking. So it is the exact same scenario. It is not a problem, and for the umpteenth time IT IS NOT A SURGE. It is less deceleration, never more acceleration. Very big difference there. Research physics and "jerk" vs "acceleration" vs "velocity".

Since you just got the car, drive it normally until you figure out what it does. Then you can improve. Driving in EV mode maybe fun, but hurts your mpg.

 

opcorn:

 

Is this a duplicate post? I seem to recall you posting exactly the same thing in another thread?

Answers:

1) With a Prius, when you lift your foot from the gas a small amount of regenerative braking is applied. This is done to simulate engine drag on a normal car. Hitting a bump disengages regeneration causing the "surge" you describe. It is not a surge but a change in acceleration. Physicists use the term "jerk" to describe this sudden change in acceleration.

2) The battery never buzzes. Neither of them. There isn't anything to make them buzz. Perhaps you are describing the brake accumulator pump, which builds pressure for the power brakes. It produces a buzzing sound at random times, appearing to originate somewhere in the driver's footwell.

3) In most cases driving with only the battery is counter productive. It can be fun, but generally it hurts mileage.

Tom

 

Just ran across this post, and yeah, I was getting the same thing, loss of braking and that weird sensation of accelerating when making a right turn around a particular corner in my neighborhood. Weird bump where the side street pavement meets the main road I guess. Happened almost every time and was repeatable. Traction control loosing traction etc.

What freaked me out first time it happened was at highway speed, with cruise on and tapping the brakes to turn off the cruise, like when you come up on a car traveling slower and the car momentarily accelerating instead of slowing. Now I just turn off the cruise manually.

While both can be a little startling for those used to normal cars, they are nowhere near a case of true "unintended acceleration."

I've had that happen, mid to late 80's Ford Thunderbird, the last year of the rounded jellybean body style. 302 V8 (apparently they made only a few.) Throttle motor/controller -or something like that- stuck open, causing wide open throttle condition. Had to bring the car to a stop with both feet hard on the brake pedal, then turn off the engine. Car was on the interstate and just shutting down the ignition with car in motion not an option (lock the steering) and going to neutral would have over revved the engine and caused damage there. 10 buck part. 50 bucks in labor, 100 buck towing bill to the shop. 5 bucks for new underwear!

 

For future reference, you can key back to ACC, let the engine die, then key back to ON, and never lose your steering. You lose power assist unless the car has EPS like Prius, but you don't need power steering when moving at any decent pace.

 

Agree with all of the above. Regarding #2, one can easily repro the buzzing sound by just repeatedly pumping the brakes. One can easily do it even when the car is turned off.

 

I haven't experienced sudden acceleration, but on several occasions, when coming to a stop, my engine raced without producing acceleration. I could even shift into Park and the engine would continue to race. The AC was off, and the engine was warm, so these conditions would not account for the high RPM. (2004 Prius). Also, the floor mat was clear of the accelerator pedal.

 

Stop calling her a liar
1. my 2010 has shown this brake phenomenon on a rough surface a few times,, but it has nothing to do with wht she has described.....also, this is a routine route for her.
2. BTW my car has enough power to spin the front wheels

 

calling who a liar?

 

Enough power to spin the front wheels straight ahead on dry pavement? It says Prius on it somewhere? I'll trade you!

 

I don't think anyone is calling her a liar. They are simply clearly describing the most likely cause of the situation that, being unfamiliar with this effect, she may very well have misinterpreted, as many before her have.

It is really important to remember that when humans experience something unusual or unexpected, they are hard wired to sort through their memories for something that might explain the pattern. This doesn't mean that the human brain comes up with the right answer or that the human, when reporting the feelings they had, is lying about the experience. It simply means that sometimes humans aren't the best and explaining what they experienced or witnessed.

Accepting this and depersonalizing the discussion might make it easier for you to process the replies you are getting.

 

Re: Sudden Acceleration - Happened To Us Today

Tashome. I have not had any repeat of the sudden acceleration since Toyota did a recall of the accelerator pedal quite some time ago. I have always suspected that they made some other adjustments at the same time - maybe a software adjustment. But either way, I am glad to feel more comfortable in my car now.
No problems with a racing engine in my 2008. I would love to get the plug-in model but just can't justify the money for a new car right now.
Thanks again.

 

No software adjustments were made. The Prius has never had any SUA problems, but in an abundance of caution, Toyota decided to chop off the accelerator pedals to make more room for people installing the wrong floor mats. You can't always save people from themselves, but you can try.

Tom

 

Or more accurately, the Prius did have SUA problems in the press and in public perception. Just not any in reality. It amazes me how many people still think that this ever was a valid problem with the Prius. In every instance where the car DID accelerate to the surprise of the driver, it was shown that the accelerator pedal was pressed instead of the brake. That little black box was a life-saver for Toyota, though it still can't overcome all the BS press that was generated during that time. Many of the comments on this thread are proof of that, unfortunately.

As KornKob pointed out so pleasantly - nobody is accusing anybody here of lying. Only of misinterpreting the feel of what happened. Brief loss of deceleration most definitely feels like acceleration. And in some ways we could even make the case that less negative acceleration could be considered more positive acceleration. But none of this means that the car started going faster during the brief period of no braking. It only means that the car stopped the expected slowing and made it *seem* like it was accelerating. Another difficulty here is that we're dealing with an account of the situation that is one person removed from the experience.

 

By Bill Visnic, Senior Editor | Published Jan 18, 2012

Toyota and Electronic Throttles Cleared - Again - in New Unintended Acceleration Report

 

YES! I have a 2010 Prius, and almost killed my elderly mom! I pulled over to the side of the road, so I could get something out of the back seat, and the car starts rolling. It was in gear with the emergency brake. Okay, granted, I shouldn't have done that. But when I finally managed to jump in, I immediately put my foot on the regular brake, and it didn't stop. Neither could I steer. I had to push the on/off button, then on again before I could stop it. I have been driving for 40 years, and this car for 2 years, and have never experienced anything like this. It was like the car was running, but the interface to the driver was dead. By the time I got it stopped, it was halfway into the street (fortunately no traffic). On the other side of the street was a very steep embankment.

Something strange happened again a few days later, where I stopped on my street to talk to a neighbor, and had my foot on the brake, again, left it in gear, idling. A few minutes later, I took my foot off the brake, hit the gas, and nothing happened... it was dead like the other incident and not responding. Again, had to turn it off/on.

Of course the dealer couldn't find anything wrong, and made me feel like I was a bad driver and making up the story, just like you. What's worse, they told me the black box showed that numerous times, the brake and gas pedal were on at the same time. I have NEVER done this in my life. Never used my left foot to step on the brake. So to me, that proved something was wrong with a sensor or the computer or something. But again, they just refused to admit anything was wrong with it and I said, Ëither something is wrong with the computer in the car, or you are accusing me of lying." The manager of the service department just walked away.

I called Toyota, and they were no help. They didn't believe me either. I am not crazy; I am a small business owner and a good driver. I went the next day and bought a Honda, because I will not drive that car again. I will also tell everyone I can not to buy a Prius. Toyota needs to stop treating people as liars and admit that things can go wrong with the software in a car.

 

Funny how this stuff never happens to anyone we know that could be considered credible.

 

This member joined today in order to reply to the original poster. If you almost killed your elderly mom, what about you since you were the one driving?. Even James Sykes would not buy this story.
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Yes, I joined today, because this incident with Toyota Service happened Weds, and this was the first chance I had to look up on the internet to see if this has happened to anyone else. The post I responded to was the most recent one I saw.

What a stupid question. Of course I could have been killed too, but at least I had a chance of jumping out of the car... my elderly mom did not. And it's one thing to kill myself, but had I jumped out and killed my mom, it would be rather hard to live with. It was a very traumatic experience; one that I don't care to repeat. Ever.

I don't know if this post is a lame attempt by Toyota to discredit me, or whether you think somehow I have a motive to make up such a story other than to warn others. Maybe you are the type of person who just craves negative attention or feels good when they put others down.

I find it interesting that another poster said, Gee, it's never happened to me... Well, some cars get problems with their brakes, or electical system... it doesn't follow that since I haven't had those problems, you didn't either.

Believe or not; I really don't care. I know what happened, and I will never buy a Toyota again, and will tell anyone I know what happened. Had Toyota taken me seriously, and even attempted to find something wrong, I wouldn't have that attitude. But it seems there are plenty of others telling these stories, and not being believed. I'm just grateful that no deaths resulted in this. I don't see these kind of stories being told about other car manufacturers.