YIKES: Experienced unexplained acceleration, already had brakes reprogrammed

Probably you used it after having just started up, in those cases it will only go to about 10MPH, If the car is warmed up it'll go much higher. I use it to look for a parking space.

 

Thanks for that lucid, precise explanation.

I don't own a Prius yet, but I have one on order. I am naturally curious about any malfunction reports. I really don't have any right to quiz you about this, but would it be possible for you to supply further info? Please understand that I am not attepting to badger you, discredit you, or otherwise cast doubt on your account. I just want to have a better understanding of what happened.

1. Was the car fully warmed up when the incident occurred?
2. How long had the car been running, and at what approximate outside temperature?
3. You say the road was wet. Was this from snow, rain, other cause?
4. Was it snowing or raining at the time?
5. Any chance of ice on the roadway?
6. You say "...smooth, wet, paved road..." Was this blacktop / asphalt pavement? Concrete? Other?
7. Did the roadway feel slippery to you at any time (car losing traction)?
8. Did you feel like you were coming into the curve "hot", possibly a bit fast for conditions (not trying to imply anything here), or just the opposite, very slow? Any noticable body lean / side G-force?
9. Did you notice any kind of error light or audible alarm from the car at the time of the incident?
10. Was this on level, uphill, or downhill grade?
11. Can you estimate the curve degree-- 90? 45? Other?
12. Can you estimate your speed going into the curve, before you took your foot off the accelerator?
13. Were you using cruise control at any point during this trip before the incident occurred?
14. If yes, how long before the incident had you cancelled cruise control, and how did you cancel it (brake, or control stalk)?
15. You say that you "...felt and heard a notable surge..." Can you be more specific? For example, did you hear the ICE RPM's increase or hear other sounds? Did you feel a definite "seat of the pants" acceleration-- positive G-force telling you that the car was defininitely picking up speed?
16. You say, "...the unrequested acceleration seemed to stop as soon as I engaged the brake..." Can you be more specific? For example, if you heard the ICE at a high RPM before you hit the brakes, did RPM's reduce immediately upon touching the brake pedal?
17. Did the car slow down as expected for the force you applied to the brake pedal?
18. Did the car return to what you would think of as completely normal operation after the incident?
19. Can you say date and time when the incident occurred?
20. Can you say exactly where you were when the incident occurred (what highway, and approximately where on that highway)?
21. Other than the brake recall issue, has there been anything else wierd or unusual that you can report about your experience with this car, either before or after the incident?
22. Did you report this incident to your dealer so they can check for error codes?

Thanks for any further info.

 

You remind me of the real pain in the neck occupant of the complex when I was president of the HOA there. The answer to your questions 1-22 is loss of traction due to wet road.

 

If the original poster follows his past practice, we won't hear from him again for two or three months. As for technical questions about this incident, this is how we fault-isolate. It isn't the number of questions as much as the answers, if any, that count.

Bob Wilson

 

Gee, how could I have missed that? Thanks so much!

 

There are people who are habitual NHTSA filers and refuse to educate themselves on the true nature of the problems they're experiencing.

 

It usually takes more than one posting to establish a pattern. Even then, the best answer is a phlegmatic reply focusing on facts and data. But after 'turning the cheek' enough to establish the pattern, use the ignore user list and/or ask the moderators if this is a problem user.

In this case, the infrequent OP has probably found something else to do. Our questions are probably "howling at the moon." So don't worry about it.

If this is an intermittent problem, it will return to others. They perhaps will stay long enough for us to try and replicate their conditions and possibly figure out what is going on. As for the 'hit and run' posters, we really do have better things to do in life. <grins>

Bob Wilson

 

The OP has already filed with NHTSA twice, and seems to want to encourage others to do the same without fault-isolating first. We've given plenty of phlegmatic replies focusing on facts and data earlier in the thread, but the OP is still MIA.

What fun is the ignore user feature and I wouldn't bet on the moderators doing anything if we have posters like malorn, apriusfan, wwest40, etc. around.

 

Jesus !

Do you work for Toyota or the any of the plaintiffs vs Toyota ?

 

Nope. Just too much time on my hands on a Saturday morning. Sorry-- guess I went overboard.

 

That is the problem with these issues. If it cannot be replicated, no codes showing no way to find answer unless this happens when it is test driven by a rep, highly unlikely.

 

Do you not rule out the possibility that the engine was off, seeing as you were going so slow around a curve without accelerating? If so, if the car needed power to avoid slipping the tires it may have engaged the engine at that point, which is probably what you felt. Cars do slip and slide even a slow speeds sometimes.

 

Thanks!

Intermittent problems are the most maddening. They are difficult to reproduce but they have a tendency to come back until resolved.

Any grade? Turn signal on? Using defrost?

Bob Wilson

 

Go outside.

 

No, I disagree. I think going to NHTSA first thing is correct. Hopefully they and Toyota will look at the "black box" and see what happened. Of course if all that happens from the incident is the news media making more fubar out of it that won't help.

Finished reading some of the replies. It is too bad you can't force an examination of the car if the incident is still traceable. But I don't know what sort of "black box" the Prius really has in it or for how long it holds various data. I would think Toyota and the NHTSA would be very interested in the incident especially since Brake Override worked and the driver was not in a panic. Other acceleration incidents may be similar to this but clouded by mention of the accelerator pedal--which in this case is not a factor. Who knows? But why ignore it?

 

There are people who've gone to NHTSA because their cars surged into the middle of an intersection in the rain, thinking their brakes have failed (hint: it's loss of traction), and we actually have a poster a while ago who did just that. Common sense and fault-isolating go a long way.

 

Or since it was in the rain and you were going slowly the engine could have popped on to charge the battery or heat the car - at the time you should have had your lights and wipers on and likely had the heat on as well.

 

I'm used to working on 'Tiger Teams' where groups collaborate on a problem. The NHTSA and SMART are teams that share our goals, fault identification, although they are better equipped and funded. We know how to notify NHTSA but it is an open question about how to notify SMART.

I'm happy the OP shared their experience with us and more importantly, came back to share more details. Intermittent problems are maddening because they often require a rare combination of multiple events, like 'brake pause.' It usually takes multiple occurrences before we can form a testable hypothesis.

Bob Wilson

 

there are also people who panic the minute an unexpected event happens and goes running to authorities with only a minimal desire to determine what happened and what they could do on their own to resolve it.

the latter requires gathering facts, other user experiences, etc. there are multiple methods to do this.

some people may consider PC a waste of time, some consider this site a valuable resource.

without speculating what the OP's opinion of this site is, the only thing i wonder about, is why did he post here to begin with??

**edit** deleted speculation comments