NHTSA Tracking Braking Loss on Prius Hybrids

I HAVE had my Prius go a foot or so farther than I wanted it to while trying to brake and make a corner when the 'scariness' has happened. Is it a 'huge' safety issue? For me, no. I can see someone totally freaking out over this happening the first few times and potentially panicking and losing control but so far that apparently hasn't happened but just wait... I can't believe that four people died because their accelerator pedal was stuck under floor mats. A tragedy but proof that strange stuff happens sometimes...

A product, like a car, shouldn't go around freaking the holy hell out of people on rough road. Accidents or not. A product shouldn't have to claim human life before something is done about it. But that said, I'm generally pretty happy with my car (above issues excluded)...

 

I'm willing to bet it is not the "Toyota Way" to wait for a death to occur before they investigate an issue. Floor mats safety and rusting spare tire structures initially sound far less of an issue than brakes. This is another black eye for the company and for this car. Unfortunately, another reason to not get the first year of a new model/generation.

 

I roll my back (not front) windows down while backing -the existing beeper can be heard a bit outside - but since I don't look where I'm going, I always also yell "Beep Beep" to the tune of the existing buzzer - I find it a better warning. This way, since I'm not watching my surroundings, I feel safe. Unless of course (YIKES) the person walking is deaf, or has their hearing aide turned down.

Now with that, I am very worried. Maybe a bright strobe light on top of the air wing????

Edit: Helen Keller reference deleted due to possibly poor taste.
Edit2: Just for reference - there was never a Helen Keller joke - the edit was the joke.

 

:jaw:

 

Actually, my wife lost control of her temper and accused me of crazy "road rage" driving endangering the baby when it occurred when she was a passenger.

On a more practical note, it would not impress my clients if I did this with them as passengers either so it is not an entirely harmless defect. Keeping a car in good repair is supposed to be a sign of a responsible person. Driving around in a car with braking issues does not impress people at all.

 

Well, but ok... I had a huge Mercedes SUV and STILL occasionally had people walk behind it too while I was backing up! Some people appear to have a death wish and nothing will stop them unfortunately...

 

Please show the proof of your tests and how you measured that "12+ inches.

I was able to recreate this in by backyard garage/lab. I pulled into the garage at 3.1416 MPH, and have shown that I can re-create this once in 32.2 (f/s2) times. On average, the stopping distance is actually 9.8 (m/s2)" less than a normal stop.

This clearly shows something different from what you see.

 

Jeez- she said "or so"!

 

Which is why I said 12+ inches (that's the or so). This caused me lots of time consuming garage research. I think in the end it was for a worthy cause...

 

For your supposed knowledge you've got it wrong. First it has nothing to do with panic stops/braking.

When there is a panic stop the regen is bypassed entirely and the hyrdraulic system is the only one in force. The Brake Assist feature of the ABS puts the full force of the brakes in action and the car comes to a screeching stop...right away.

This is NOT the case being discussed here.

The case being discussed here, admittedly you know nothing about the vehicle and its technology, is completely different from anything you might have encountered in your past life. It's beyond your scope of knowledge. The case being discussed here is a mild braking situation, that's when regen braking is utilized.

That last paragraph is pile of misinformation that is as bad as the LA Times garbage that it's trying to foist on the public. The sentence about the Lexus floor mats is nonsensical. You contradict all the fact and evidence over the last 4 yrs. You also appear to believe that this is the first winter that the Prius has been on the roads. Are you for real? Do you realize that there are hundreds of thousands of these vehicles all over the world in every climate?

You suddenly appear with your first post and begin spouting tripe as if this is something new to the world. Please remove yourself back under the bridge. When you get some experience and seat time then you can bring a little, a small amount, expertise to the discussion.

 

Seriously on this issue. You are supposed to honk your horn at all times when you back up any vehicle. That's safe and polite. A quick 'Beep' is all that's needed. I learned this 40+ years ago.

 

Isn't this happening only from regenerative braking?

A driver using only regenerative braking from 60 mph will have a stopping distance close to 1000 feet on an increasing-force (constant power) profile, or much longer on a constant-force profile. I don't believe that an extra 44 feet should be an issue. If it is, they should be using friction braking instead.

I keep having to return to the example of ABS introduction in a previous generation. Numerous drivers reacted poorly to the unfamiliar response, leading to some crashes.

How was that handled? How must the response to this Toyota Hybrid issue be different?

 

I cannot believe this thread went so supersonic. I knew this would be blown WAY out of proportion.

I love you all, I love you more than life itself, but your all [flippin'] mad!

 

I had the same issue when braking on uneven surfaces with other vehicles that have ABS. I believe it is a function of ABS and not regenerative braking. I also think that the issue can be remedied with some software tweaking. One car that I owned that many owners complained about was a 2002 Subie WRX. That car exhibited it more so than other ABS equipped vehicles I've owned. Bottom line... the more complex our vehicles become the more complaints you will have from people that are unfamiliar with the technology that runs their vehicles.

 

I stand on my thought that a *loud* vocal *Beep* *Beep* is plenty sufficient (providing your rear windows are open). No need to use the annoying horn. Also, no need to even look around and pay attention to your surroundings. Just shout it out...

 

I haven't followed this crazy thread that closely since I don't own a 3rd gen and have insufficient seat time in a 3rd gen to be able to compare the behavior of a 2nd vs. 3rd gen.

(Yes, I've reproed the skid light coming on when hitting a bump and braking at the same time causing an odd sensation.)

For those who keep bringing up ABS or trying to compare to other non-hybrids w/ABS, etc. the stroke simulator was brought up, I seriously doubt those other vehicles had a brake by wire system and stroke simulator, let alone regenerative braking.

See Prius tech training and http://www.autoshop101.com/forms/Hybrid16.pdf for some insightful info on the 1st and 2nd gen Prius' brakes. I'd be very curious to see a document detailing the changes to the 3rd gen's brake system design, if any.

 

comment deleted

 

Video Library - cbs5.com

The reporter didn't quite get the effect right imo- but I guess he's basing his statements on the NHTSA reports. I never felt a "lunge forward" or any kind of forward acceleration when I had my brake loss happen. It simply kept moving at the same rate when it should have continued to decelerate.

Still, it was nice the guy being interviewed hasn't experienced the effect- and his blizzard white looked GOOD in the light rain we've been having!

And, it was even NICER to see that Toyota has made some kind of a statement and is aware of the situation and is looking into it.

 

That's a great question. I doubt very much it would happen at higher speeds. Would this be an indication that it must be the switch between regen braking and friction braking?

Is most of the braking that happens at higher speeds regen braking? At what point/pressure do the friction brakes kick in?

I'm asking because I wonder if we could rule out ABS as being the culprit if it never happens at higher speeds when ABS and regen might occur together?