Brakes - Scared the SH!T Out of Me

Amen brother. I drive an Audi RS6 on the weekends. Hit the brakes at high speed on any kind of washboard surface and you are in for a load of fun. This is just how ABS works. Of course, without ABS you'd be in the ditch so a little wackiness is worth it.

 

TRAC, ABS, VSC... whats it all about??

well, its easy, we had the chance to manage our own driving habits and we SUCKED at it. now its the car's turn...

mark my words, LKA, ACC, VSC, etc... will all be required standard equip in less than 5 years. the technology simply takes the capital letters out of "human carelessness and inattention"

 

So what is 'electronic brake distribution' supposed to do if not compensate for one tire's momentary loss of traction?

 

Darwinism in action ....

When I growled "tell your story walking" the scrawny little bugger looked as if I had slapped him in the face.

I can only think of two situations where that would be true: a gravel road, especially a washboardy one; and, deep snow

Otherwise, in "real world" conditions that one must drive in +95% of the time, things like brake assist, VSC, ABS, etc, are very much desirable

My FJ makes a very good compromise of electronic safety aids: in 2H, the Trac is very sensitive, along with the VSC (Though still much better behaved than the 2004 Prius I used to have).

In 4H, the VSC is dumped (The VSC warning light turns on to remind you of this), and Trac is detuned. You will notice that if you're dumb enough to drive in 4H on an icy road, since the FJ has close to 60/40 weight distribution, the back end will start to weave around. Shift back into 2H, that immediately goes away

In 4H, the Trac will get you into trouble if you're on slick clay or slippery - but shallow - mud. It will act like an over-sensitive rev limiter, and if you try to goose it to get out of the slick stuff, the motor goes "budda budda budda budda" as power is repeatedly cut and applied, and you will come to a stop

In 4L, the ABS and Trac are dumped. Those warning lights are also turned on to remind you of this. In 4L, driving on a washboardy gravel road, if I stand on the brakes, all 4 lock up and the FJ at 50 km/h will usually stop a car length sooner than if the ABS is active

But in normal real-world driving, I want all the safety aids working properly. Perhaps it would be nice to be able to defeat them, so when you do bog down it would be easier to get going

 

I believe that's the compensation for weight bias in the car, proportioning brake force between front and rear braking action as load distribution changes. I think it was on pickup trucks long before ABS became common, made its way to cars and now integrates with the other controls.

 

A related question--in a Car and Driver article they complained about the Prius' VSC not being allowed to be disabled or adjusted. They implied that it would make it impossible to get unstuck in snow. Is this true?

 

VSC has absolutely nothing to do with getting stuck in snow, other than it might keep you from losing control and sliding into a snow bank. Traction Control is the system that controls power to the drive wheels in slippery conditions.

Earlier Prius were paralyzed by Traction Control if they were stopped in slippery snow or uphill in gravel. Starting in 2006 the Traction Control algorithm was improved, making a Prius less likely to get stuck and more able to drive out of snow. The main purpose of Traction Control in the Prius is to protect the drivetrain, not improve traction, so it still can be a liability under adverse contions. Other traction control systems, like those on the FJ-40, apply selective braking to improve traction. Many of us are hoping this technology has been applied to the 2010 model, but no one has had the opportunity to test a 2010 in winter conditions.

Tom

 

Thanks for the info. FWIW, here's the link to the C/D diatribe--er, ah, *article*: 2010 Toyota Prius Comparison Tests - Car and Driver

They do say "what happens when the Prius gets stuck in snow?" (My answer is, I'd get the shovel out of the hatch and clear the area around the wheels...) They seem to take great joy in bashing the Prius on the supposed grounds that all owners are smug, the car isn't "fun," everyone should drive a 335is, yadda yaddita yawn.

They gushed all over the Honda Insight. I drove it, and it's not a *bad* car, but you do get what you pay for on this one, IMO. Off topic, sorry...

Cheers
Tim

 

Everyone who owns a Prius will eventually experience this issue when going over some sort of bump, pothole, ice patch, etc. What possible information could you have that cannot be shared in the thread here? Mighty suspicious post if you ask me.

 

What did the dealer say?

BTW: your description does NOT match the problem currently in the news and tracked by NTSB (which is a cut-out, not a grinding noise)

 

Does anyone ever read the manual? I have a 2001 Volkswagen golf with ABS. it stAtes very clearly and in bold print that ABS is not designed to reduced stopping distance(and in fact specifically points out that under certain conditions such as loose gravel stopping distance can be greater with ABS), it increases your ability to steer while braking hard, hopefully to avoid an obstacle. All this non-sense about stopping distance is silly and irrelevant unless you are about to smash into a large barrier around which you could not steer.

 

Looks like yet another prime candidate for selling their death trap Toyota. It's just sad.

No one here knows the Prius? Well, that's certainly not the case.

Crazy people sensationalizing a "perceived" "problem"? Bingo.

Maybe FOX news has better info in a 60 second spot than 5 plus years of actual Prius owners. Yeah, that's not funny at all! Please, people, you're dimming my view of where we as a species is headed...

 

Don't let the door hit you in the nice person on the way out. lol

 

Hah hahahah hah hahahaha!

 

NO!

It's the floormats ... er, the computer .... er, the regen brakes ... er, the friction brakes ..... er, the gas pedal stuck wide open yet I was applying the brakes .................................................................................................................. er, it's media hysteria + the competition stirring the pot. Nah.

Do some research before you panic. At this point the damage is already done to Toyota. Audi faced the same groundless charges and it nearly destroyed the company. I expect the same to happen with Toyota.

-Brad

 

My FJ Cruiser owner manual dedicates 1.5 pages to warnings about the ABS, many with yellow highlighted text. The primary warning is that ABS is NOT designed or intended to REDUCE stopping distance

These systems may be a helpful driver aid, but they are not perfect. A recent Tire Rack test of winter tires at a test track in Sweden

Winter Testing at the Arctic Circle: Studless Ice & Snow

concluded that even with a Traction Control system designed to allow wheelspin, such as those found on the BMW test cars, the TC did NOT allow enough wheelspin to gain maximum benefit from the winter tires. You will gain maximum traction from a winter tire by allowing 30-60% wheelspin

 

Just in case OP can not get his seat clean
Costco - 100% Genuine Sheepskin Seat Cover

 

Well, as has been pointed out to me, and it is reality, Prius Chat IS a Prius Enthusiast website. It's grown to encompass more, and I think it does, but why are you suprised it is full of Prius enthusiasts?

Yes, imo, if you post anything that can be interpreted as negative towards The Prius, there are a percentage of supporters that almost ALWAYS respond defensively and in the positive.

But starting at the first of this thread I didn't read a lot of people trying to mislead you. The brake "issue" has seen the entire spectrum, from numerous posts from people proclaiming it the end of the world, to numerous posts from people who claim it is nothing. Since Toyota has responded by updating the software, at least in the latest production run, I think the truth is somewhere on that scale between the two extremes.

But how angry or upset should you be within Prius Chat and with owners that love their cars maybe even to a fault?

Oil on the road, tire dressing, it's no big deal, were all opinions I think offered in sincerity. Even with the software update, I think the braking issue has always been defined in degrees of individual perception of the problem. That's why the issue was so mercurial and so hotly debated.

My advice would be to avail yourself of the software update when it becomes available. It might just be the answer for you. Rethink abandoning Prius Chat. It's a reflection of humanity. Which means I think you'll find Trolls of Negativity....and Prius Purists of Perfection...but overall, I think you'll mostly find reasonable people trying to reasonably be of help.

Take what you want and leave the rest.