Any reports of unintended acceleration in Priuses?

There has been some reports of cruise control initiated acceleration but the most vocal, Woz, apparently didn't understand how stacking 'ACC' pulses along with automatic cruise control might lead to rapid acceleration. Speculation but thinking is the automatic cruise control was holding the speed constant while 'ACC' inputs were being fed into the computer, waiting to be released. The leading vehicle moves aside or a lane change and suddenly all of the previous 'ACC' inputs activate the accelerator. This is a rare event and debatable on whether or not it is a fault or a feature.

Bob Wilson

 

This thread contains interesting info, specifically someone downloaded the NHSTA's complaints DB and is summarizing it...

http://priuschat.com/forums/gen-iii...eport-accelerator-weakness-7.html#post1077222

 

It takes 2 seconds to shut off the car or put it in netural, geez

 

"unintended acceleration"?

Occasionally happens to me - when I forget I had the "POWER" switch left on at the next stoplight.
Zoooooooooooom. Geez Louise, the Prius can surprisingly haul......:car:
Can't blame Toyota for the unintended-thing; just my dementia.

 

Toyota should be the safest cars to insure because no one will ever say the accident is their fault.

 

And tickets?
"Gee officer, I was stopped at the intersection and my Toyota accelerated all by itself making that left turn on red".
May coin a new word - "Toyofault"

 

I love my Prius but uncontrollable acceleration is the least of my worries in this car. ound:

 

It seems likely sometime and somewhere a Prius drove off a cliff and experienced unintended vertical acceleration.

 

Okay - my 2007 Prius is the most reliable car I've ever driven. I love it and plan on driving it for years to come. 60K+ and works great. That being said, guess what? I did experience unintended acceleration - it happened in June 2009. Two people in the car with me. I was on a residential street, made a sudden right turn (due to my wife's nagging me) and floored it to accelerate - that's embarrassing. I got up to 25 or 30 backed my foot off and the car kept accelerating. I tried to lift the pedal with my foot, don't know if I could get my toes under it, that didn't work. I leaned forward thinking I'd grab it with my hand - started worrying about the air bag going off and abandoned that. The street I was on terminated at a stop sign at a Tee intersection on a busier street so I decided I needed to get the car stopped and hit the brakes while trying to get it into neutural and hitting the start/stop button. I was embarrassed because the whole incident started with an emotional driving manuever. Was it the floor mat or something else? I'll never know for sure. I do know that I have a heavy rubber floor mat over the Toyota floor mat. If I kick it repeatedly I can't get it to budge. I've solved a lot of hardware and software bugs over the years and my best guess is an extremely narrow timing window - but then again maybe it was the floor mat although I can't see how. Well, now you've seen my first and last post on prius chat. I don't want any attention and don't worry about the problem ever occurring again but if others have seen the same - even if it is the floor mat - I'd be interested.

 

Considering that floor mat issue is a recall for your vehicle I would, at the very least, take those extra floor mats out of the car. Why would you leave them in after what you experienced when incorrect floor mats are what caused that Lexus crash (iirc)?

 

Bob,

In my experience with the adaptive cruise control, the car behaves differently depending on the gap between the "set" speed and the car's actual speed. For example, if I have the cruise control set to 70 and I am behind a truck going 40, when I change lanes the car accelerates very rapidly. On the other hand, if the cruise is set to 70 and a car in front of me going 65 changes lanes, it will take quite a while for me to return to 70.

All this is great on the highway (where Toyota intended it to be used). It is so subtle at times that I find myself going 20 mph slower than I expected because a car in front of me slowed on the freeway.

On smaller roads when I have the cruise set to 40, if the car in front of me slows just slightly, the Prius will slow much more quickly than necessary (translation: than I would slow if in manual control). Part of this may be Toyota's engineers being conservative about the smaller gap betwen cars at slower speeds. I'm not sure, but it is pretty noticable. I don't mind it, but my wife mentions it when she is with me.

I don't think it is a backlog of commands that causes the rapid increase of speed you mention. I think it is algorithmic. Given the speed of the CAN's (there are 2 in the Gen III), it is unlikely that network or processor backups can occur.

Bob

 

NO unintended acceleration with my P3 - still now but is there any reason for a change ?
I don't think so. Don't use a lot the cruise control.

 

Brought my 2010 Prius V w/AT package in May of 2009. I had experience no problems with the Prius as this day. My 2010 Prius is working just fine.

 

nope, I only have experienced "intended accleration" mostly in "POWER" mode

 

I assume you are referring to the fact that each push of the cruise control accel switch increments the set speed. Which is, of course, perfectly normal behavior. It becomes surprising behavior when the car is being "held back" by the radar cruise control and then the obstruction in front goes away. The car accelerates to the set speed, which might be considerably higher than the speed prior to the obstruction travelling in front if the button has been pressed in the meantime. Without counting button presses, the driver has no way of knowing what the cruise control set speed is.

In this day and age of cheap multifunction displays and associated technology, the solution seems simple. Display the cruise control set speed on the dash. This is how an autopilot works. The car's multifunction display should be leveraged to display the set speed and an "enabled" indicator. Pushes of the accel/deccel switches would change the set speed on the display. The driver will then always be aware of what the cruise control is set to, even if the car is going slower than that. And they'll also be aware of the state of the cruise control: "Off", "Armed", "Active" or "Radar Following".

 

The "set" speed is shown when DRCC is enabled, just to the right of the DRCC display. I guess you would have to be looking at it, or glance at it, but it is certainly there, I always know what my set speed is, as I am increasing it...

 

reflecting on the recent spate of SUAs on the Prius. If memory serves me correctly, Audi was in the same boat in the 80s with the Audi 5000. 60 Minutes had shown a segment where the car ran out of control when there were several reports of the Audi exhibiting this issue (tidbit, 60 Minutes was found to have jimmied the transmission in order to exhibit this issue (Brian Ross syndrome)).

One common thing the Prius and the Audi 5000 have...
both cars have the front seats canted inward a wee bit so that they are not parallel with the body. I wonder if the slight inset is enough to throw people off and have them press the throttle instead of the brakes?

(FYI: the Audi 5000 was proven by the NHTSA to be all driver related errors. all the drivers pressed the throttle iso the brakes when the cars were in operation)

 

There are over 500 NHTSA unintended accelaration complaints on the Gen II. None so far (that I have seen) on the 2010.