Video: Toyota demonstrates "Safely Stopping Your Toyota Hybrid Vehicle"

Over 62mph, shifting to N can over manage MG1 (transaxle). I think that's why they put it in the manual not to do that.

 

So now I'm a little concerned the computers might refuse to go into N at those speeds. Anyone have the source code? Anyone dumb enough to try it? I've done it at 40, but I ain't doing it at 70

 

I thought I read not to be in neutral above some numbers in the 40s with the gen 3. I can't remember the number. I have not tested it above 35. I don't like to practice potentiallye unsafe things on a new car based on forum advice. I'm sure someone else has done the test at 90s I'm not willing to do that.

 

Yes and at 100mph. The engine stopped reving and I started to slow down. Shifted back into drive at 65mph and continued on my way.

At 100mph and full throttle the brakes will work and slow you down also.... QUICKLY!

 

One point here is that ClownBoy was in an '08 Prius, and the
excerpt is from the *2010* manual. So he wouldn't have read it.
.
The larger point is that it *shouldn't be*. The 2010 transaxle
and shifting stuff works just the same as the generation prior,
and that big hairy warning is in the manual IN ERROR. There is
absolutely no harm shifting into N, as has been reaffirmed hundreds
of times in other threads. At a minimum the section should be
removed, or for more clarity rewritten [in the other section that
talks about shifting] to simply list some caveats about N and
braking and timeouts. Do *NOT* interpret what I quoted as any huge
caveat about the 2010 or any other year of Prius -- it's largely
WRONG. I just don't recall anyone pointing it out on the forums
until now [but could easily have missed a mention].
.
The only real hazard of Park would be in the *first-gen* car,
where it's still a mechanical linkage. N is safe there too.
.
_H*

 

Is the max deceleration rate limited by the max rpm of the MG1 ?

The ICE rpm cannot be dropped to 0 at a higher rate than allowed by the MG1. In fact, the higher the speed, the slower the ICE's deceleration has to be or equivalently, the earlier MG1 hits its max rpm.

Interesting stuff.

 

No. All drive power can be removed at any speed.

At higher speeds, the ICE must keep turning to avoid overspeed for MG1, but the ICE does not have to produce power in this mode. It can spin without fuel or spark.

All of this talk about the dangers of N at high speed come down to one very specific and unlikely scenario: shifting to N at lower speed and then costing to a very high speed. At lower speeds the ICE physically stops when you shift to N. If you were to coast down an incredibly steep hill, the Prius would gain speed without being able to restart the ICE (not allowed in N). At some point, if the coasting speed gets high enough, MG1 will overspeed.

It takes a *lot* of energy to overcome drag at high speed. Very few grades are steep enough to do this. This situation is not likely to ever happen in the real world. In the event of an emergency, you shouldn't even consider the risk of hurting MG1. It's not going to happen, and even if it did, it's just a piece of machinery.

Tom

 

I have tried it above 62mph. The car is smart enough to keep the ICE going at RPM to prevent MG1 from over-revving.

Tom's post is accurate about the only danger in N. That's if you shift to N at 55 mph (ICE RPM=0) and let the car coast in N above 62 mph (hill has to be very steep and long). It has been said that ICE will remain at 0 RPM even when the car goes above 62 mph and MG1 rev above 10k RPM.

Toyota may have closed that loop hole in gen3 Prius. Can anyone with gen3 and scangaugeII confirm it?

 

My 2009 manual, p.126 has the warnings you first posted about not shifting into R, N or P while moving ... damage to transmission may occur.

 

Putting the car in N or, if that doesn't work, powering off, is covered in the 04 -09 floor mat recall letter.

 

How low does the ICE rpm goes before the ECU considers it "physically stopped" ? I would think it is somewhat higher than 0 rpm.

Can the wheels drive the ICE ?

 

Physically stopped is stationary. Not only does it stop completely, but the Prius parks the ICE at a particular point to make restarting more efficient.

Yes, as long as MG1 provides back torque to prevent freewheeling.

Tom

 

Wow that's too bad you didn't read all the warnings splashed ALL over the video to (before playing) BEWARE ... due to foul language. This is exactly why folks can't stop their cars ... no one seems to bother reading the instructions. What do you want a bet ... back 70-80 years ago when the 1st key ignition/starters were installed ... and mechanical throttles stuck open ... no one read up on how to turn a KEY off. As it was written thousands of years ago, "... there is nothing new under the sun ..."



.

 

Could you please repost this, but use smaller words?

Tom

 

:lol:

.

 

oh you guys. I want to be as smart as you, but I'm too nervous about the consequences of making any assumptions. I went out and tried using the P button while accelerating. It worked perfectly. Car went into neutral and it beeped, I guess to warn me. I was able to shift it back into D with no problem. Showed my teenager how to do it and was quite content. Then I come back to Prius Chat, which I feel I must do now in order to be absolutely sure I understand everything about this situation.

I did not read enough times that it is perfectly fine to just push the P button to put the car into Neutral and that I can do this at any speed without destroying my car, my transmission, etc. I do grasp the exception case about pressing P or shifting into Neutral using the joy stick before coasting down a long, steep hill. I actually know of exactly such a hill, so I'll try not to have a big problem right before the top of it.

At any rate, here's what I want from you all.

Please state again that Pressing P is just the same as moving the shifter to N, except that it is easier, because the button is so accessible and you don't have to hold the button in to gain the shifting into N result.

 

Is this car actually training its owners on improving their button pressing skills ?

Wow.



Perhaps none of these buttons do anything except reward the subject with what he/she thinks she wants.

 

"Pressing P is [effectively] the same as [holding] the shifter to N". It's the same, if you only want to consider the results. Inside its little brain, it quite a different story. But for your purposes, P will get you N.

 

Isn't the ICE stoppage achieved simply by disabling the spark or is there another mechanism used (MG1 perhaps) to park the ICE correctly ?
That goes back to by original question : how does the ICE keep turning except by fuel and spark , in order to prevent overspeed ?