Wozniak cites 'scary' 2010 Prius acceleration problem

Yes, while I think he was being evasive, "vague" in his first two comments, it suggests to me that he was worried about describing the problem publicly and releasing a torrent of Prius driving public to the roadways to go 80+mph in an attempt to see if the Prius will suddenly go 90+mph. I can understand his being hesitant and evasive. While I wanted the details...maybe now I'm sorry I got them.

 

Thanks!

That explains it in the NHW20 ... a dirty contact could easily spoof the cruse controller into thinking a different resistor was touched:

But the funny thing is using the cruise control at speeds above 80 mph ...

Well it's a dirty job but somebody has to do it! You' all stand back, this is a job for Bob. No need to exceed speed limits folks ... I live in Alabama and Georgia is next door. <GRINS>

Bob Wilson

ps. Danny, if you were a little closer, we could . . . ah yes, parallel cruise control safety testing . . . say 2:00 AM? Or as they say in Atlanta, "Keepin' up with traffic."

 

Glad someone summarized the problem.

Yes the problem does exist and I have experienced it several times in my hwy trips until I learned how to use the CC.

The problem is: whatever you tap on the CC lever (up or down) stays on "memory" and there is a delay for the car to respond by adjusting the speed. This could be a software-based delay but I tend to think this is simply the result of lack of adequate torque at high speeds in the Prius because the issue seems to be more pronounced when accelerating as opposed to slowing down. In other words, at high speeds, when you tap the CC lever up, it takes a while for the car to speed up to where you want because it simply has no power for quick acceleration. If you press it 10 times it will take forever to speed up but will eventually get to very high speeds. The higher the speed you’re cruising, the higher the delay.

It does take a while for folks, like me, who were used to real time action from the CC lever, to adapt.

 

Evan, I think you have it exactly. Any tap on the CC, whether up or down, should immediately cancel any "stored up" taps in the opposite direction. I count my taps and use it to precisely change my speed, but a good human interface design shouldn't assume that is normal behavior.

Tom

 

funny.

any car when on cruise control and in some conditions/situations will seem to accelarate.
because in this situation the speeds drops below the set speed and the car wil speedup.
the prius with its CVT like operation wil sometime seem to accelerate ( motor noise ) but nothing happens with the speed.

 

Hard to believe someone could be so "smart" and still not read the owners manual.
Mr. Wozniak's Cat 5 Prius is equipped with "Millimeter Wave Radar Cruise Control." It is designed to attempt to keep the set speed (displayed on the screen) unless another vehicle ahead is blocking the path, then it attempts to keep the distance set between the Prius and the car ahead.
If you set the speed at 95, and cruise behind a car going 60, the Prius will cruise at 60. When the lane becomes empty the Prius accelerates to the set speed.
IT'S IN THE OWNERS MANUAL. TRY READING THE INSTRUCTIONS!!!

 

I don't know... this is hardly a problem at all.... hitting the brakes or pulling the lever cancels the CC anyway, so what's the biggie?

I think the issue of "quick acceleration" or "lack of adequate breaking" (whatever you want to call it) when breaking is far much more relevant problem. I actually almost crashed my Prius because of that last week. I was driving on a curve with ice on the ground and gently applied pressure to the breaks, then the car gave that annoying quick jump, which forced me to press the breaks a bit harder to avoid hitting the car coming in the opposite direction in parallel; but it turns out the disgraceful quick jump resulted in a sliding off and I was millimeters of hitting that opposite car...

 

He has Prius V with laser guided CC. Perhaps an owner with the same package can try to reproduce it.

Gen2 and Gen3 Prius II-IV does not have laser guided CC.

 

watch what you are saying about Woz.........

 

Hummm, my NHW11 has a "3 tap" memory limit. I can quickly "3 tap" but subsequent taps have no effect until the car has achieved at least one tap of speed increase. Then I can add another tap. That is how I've also been driving the ZVW30.

I'll see if it can stack say "10 taps" ... along with the 85 mph test. <grins>

Bob Wilson

 

Funny how all these Toyota problems seem peculiar to the U.S., which has a car industry in great trouble largely of its own making. Are people really switching from Toyota to GM? Well, fear is a common device used in the American media and in politics these days. You know, health care, etc. It's effective.

 

Your high fiber diet is sure showing up on this message board in the form of sh*t. Another prime example of "see no evil, hear no evil."

 

Steve should stick to his cheeseburgers

 

Thank you Efusco, I think you hit the nail there, that's exactly what I thought when I read his experiment description.

This guy seriously needs to read the Prius user manual, and stop complaining to the press about some error that only exists on his head.

The sad part is that instead of trying to understand what happens, most people immediately jump on Toyota and on the Prius. Just because it's Wozzy speaking... for crying out loud, it seems the guy just wants to get in to the news...

Let me just add some more tech info: At least in the European 3G Prius the stalk increases/decreases at different steps as it is on CC or on ACC mode.

If we're on normal CC mode (constant speed) then each nudge will alter target speed by about 1 MPH, but if we are on ACC mode (radar on) each nudge will alter target speed by 5 km/h.

If we are on Adaptive Cruise Control mode and we keep the lever up for about 2 or 3 seconds the target speed can increase over 30 km/h or more quite fast. I'm betting the guy was on ACC mode and kept the lever up for some time, not just nudged it... just guessing...

I'm also not happy that he made silly claims, for someone who claims to be such an intelligent man:

"it's so wrong and so out of your normal control"

"It's scary because you don't think of things like putting the car in neutral when this happens"

"I am sure you can't turn the car off with the keyless power button, the only option on this model."

"Braking does disable this scary cruise control effect. It is a natural response, so the problem is mitigated a great deal"

Which one is it Mr. S.W.? Was the car "out of your normal control" or was just as easy as "Braking does disable this scary cruise control effect"???

Reminds me of the RTFM joke... just RTFM Mr. S.W., just RTFM... who's paying for this anyway?

 

maybe Steve should drive a Geo metro and a Ferrari with CC.


my guess is the Metro wouldn't react any quicker considering the lack of power coming from the engine and the Ferrari would blast foward with all it's power.

 

I think we can all expect to see anything, anything at all, out of the ordinary on a Toyota will immediately be blown up to be "the next thing that will kill you" on the evening news.

Fear sells.

 

I love the Prius fanboys disparage anyone who talks ill of the Prius.