Prius surged forward

OK, so maybe you're not a troll. The simple remedy is, leave the car in D. The only occasion for Neutral is when getting pulled through a carwash.

 

Right. It is accelerate-by-wire, because the gas pedal can't be tied to a 'throttle'. The Prius needs to determine the most efficient & effective method to deliver power, whether it's the engine, battery or combination. And when you're in neutral, you can press the gas all the way down and you won't hear the engine race (that would be silly for a hybrid) or have any other indication that the gas pedal is pressed. Also, you can switch from neutral to drive with the pedal pressed (I tried it at lunch today, under mild pedal pressure to be safe).

So I can definitely see somebody getting surprised when switching from neutral to drive with the pedal unintentionally down, whether by pressing the pedal or a carpet getting tangled up on it.

As for being in neutral, I do that in the first mile of driving to eke a little better MPG, since my commute is so short. After that it doesn't buy you anything, and I always switch back to drive when slowing down for the two stop signs I have for two reasons: 1) to recapture energy since neutral doesn't have regen braking, 2) so I don't try to start moving from the stop and forgot it it's in neutral - it's embarrassing when I push down on the gas and absolutely nothing happens, but I'm leaning forward in anticipation.

 

Actually, the Prius steering wheel is directly connected through the steering shaft to the rack & pinion steering gear. A torque sensor on the steering column determines needed power steering assistance and an electric motor mounted nearby provides this assistance. Hence, if the power steering system fails, it is still possible to steer the car although much more effort will be required.

The accelerator pedal transmits the driver's request for power to the hybrid vehicle ECU. That ECU decides how much power will be provided by MG2 and how much will be provided by the gasoline engine. It transmits that request to the engine ECU. So the accelerator pedal linkage definitely is "by wire".

 

Thanks for clearing up my misconceptions. For what happened to the OP to have been "the car's fault", the accelerator pedal position sensor would have needed to malfunction. I imagine that there is some redundancy built into this critical system, though, so I wonder what the chances are of failure. And shouldn't the Prius's "black box" have recorded data for this event?

 

The brake pedal is also "by wire".

Tom

 

the prius engine "revs" in park, but not in neutral.

post pics of damage

 

I dont think theres a black box on the classics, cars with the occupant classifcation system, and advanced airbags have a black box which records the speed and weight of driver. or at least this is what i remmeber

 

I have a brother who used to wreck cars. He always had an excuse for why it was not his fault and was always looking to find allies for his excuses. This sounds very much to me like one of the stories he would tell.

Until proven otherwise, I am siding with efusco on this one. Driver error.

 

Ah, forgot that this was a Classic involved.

 

Just got back from groceries. So I thought I would try a little stunt in the parking lot, with nobody around, just to see what would happen

Shift to N, received warning about not charging. Floored gas pedal, kept left foot lightly on brake, shifted to D. Guess what happened?

Nothing

 

alternatively:
1. place parking brake (to keep car from rolling forward in neutral) and wait for engine to stop
2. shift to neutral
3. stand on gas pedal. no brake. engine did not even turn on.
4. shift to drive
5. car tries to shoot forward. parking brake hinders a little bit.

if you're on the brake firmly, the brakes will hold the car over the engine revving. simple as that.

 

I think thats the point. It doesn't matter if the throttle control is by wire or not. The brake isn't. If you are standing firmly on the brake, the car can't fly forward faster than you've ever felt it move before. The mechanical brakes are fully engaged. The brake is not by wire, it just has some travel in the top range before the mechanical kicks in. It does have sensors like the steering that allow it to do other things, like activate the electric braking or throw the emergency booster. The ECUs are also smart enough to know that if the brake and accelerator are pressed at the same time, something funny is going on and it should just do nothing. Thats the nice thing about accelerator by wire.

BTW the sites you linked are well known to be the products of ambulance chasers trying to get a class action suit together and make $$$. Funny that if search the web this problem of unintended acceleration apparently plagues almost every major auto manufacturer

If you're a troll, nice try please move on. If this actually happened to you, sorry you crashed your Prius.

Rob

 

Pressing the brake + accelerator at the same time while in Drive
invokes force-charging, aka the only meaningful "engine loading"
state the car can produce. If you let off the brake during
that state, you'll get the expected rocketship effect. This is
talked about in the land speed article and I warn drivers about
it in my rally hints text.
.
Any owner that *hasn't* gone out to an empty parking lot and
experimented around with these various control quirks should
do so, ASAP. Especially finding Neutral reliably -- I've seen
far too many people totally unaware of the half-second delay.
The more in tune with the car you are, the less likelihood
that dumb mistakes may occur.
.
_H*

 

That link gives me a 404. :-(

 

works fine for me.

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