2010 Prius ABS Braking Problems?

Nah, those incidents only occurred during a 6mo media frenzy on the subject. After that all problems miraculously disappeared. LOL

 

Some of these complains are very recent.

 

It was a joke. The number of complaints made immediately following the Sikes story and other media hype increased exponentially then died down just as quickly. Sure the change over from regen braking to friction braking is disconcerting but it in not dangerous condition if someone is already driving safely. Hopefully newer systems will correct this condition.

 

I was contacted by a personal injury lawyer who is pursuing this line of argument as a cause of death involving a Prius and a train. Apparently he looked through PC to find people with some understanding of the ABS braking system.

Tom

 

Actually, not true; at least not all the time.

There are two different friction coefficients: one for when two surfaces have bonded (i.e. when the tires are rolling, so the same patch of tire stays in contact with the same patch of road) and one when they have not (i.e. when the tires are sliding on the road.) The bonded friction coefficient is always higher. Breaking that bond takes energy, and if you provide just enough tire torque to stay under the breaking point you can dissipate more while getting a slightly better acceleration. This is what ABS tries to do.

Note that this applies when the ground and the tire can bond, so this doesn't help in snow or on loose surfaces such as sand or gravel.

Though you're right that in *all* cases it helps you maintain control of the car.

 

Yup, right you are. I remembered backwards. ABS usually delivers a shorter stopping distance on wet or slippery roads, often (but not always) on dry pavement, and usually takes longer to stop than skidding does on snow or gravel.

 

I see you remember your classical physics. For ideal materials your description is correct. For the real world it gets more complex.

In practice, for almost all physical materials, the COF goes up as the material starts to slip, then drops off as the material goes into a full dynamic mode. This is the controlled slip mode used by locomotive engines to gain maximum traction.

Automotive ABS is not sophisticated enough to provide maximum COF controlled slip. It main purpose is to keep the tires turning to maintain control.

ABS will reduce wet braking distances when compared to a full lock-up, but not compared to proper feathering of the brake. It also will not reduce braking distances on loose materials that pile up under the tires.

Tom

 

I have a March 2010 manufacture II , the ABS has always worked as advertised, Tried it out on ice and snow and bare road, works well, never locked up the wheels. Sounds like a problem with your car, I would try to duplicate it and when you can, take it to a dealer for diagnostics. I can easily see that setup, you trying to make the light (like I always do) and the person in front stopping on the yellow. Bummer, real setup for a problem. Sorry about your lockup, but suspect it is a vehicle problem not a design problem.

 

I did a emergency stop a month ago when the guy in front of me ditch out of a turn lane and pulled back into mine. Was only going about 25-30 mph went from accelerating to slamming on my brakes. Had no issues and was surprised how quickly it stoped, but then this is the first car I have owned with 4 wheel disk brakes.

 

Bottom line, ABS should stop brake lockup - are you stating you had 4 wheels skidding into the accident (leaving a clear trail of rubber from all 4 tires - do you have pictures?)? I highly doubt this occurred. More likely - in the heat of the moment, you thought they weren't working - but were.... The marks on the road will tell the truth...

 

ABS will not stop four wheel lockup. ABS senses differing rotation rates between the wheels. If they are all turning at the same rate there is no way for ABS to sense a problem: As far as ABS is concerned, the car is just going at a slower speed or stopped.

Fortunately this is a rather rare situation. Generally one or two wheels lock first, allowing ABS to activate.

Tom

 

To all of you Toyota apologists: The brake failure on a 2010 Prius while braking is very real. I had noticed this on my car at 2800 miles and complained to Toyota and filed an NHTSA complaint as well. Several times. What happens is that the regen braking cuts out after going over a bump, requiring more brake peddle pressure and gives the sensation of surging forward because the rate of deceleration is decreased. It can easily be reproduced. Finally, I had a complete system failure, with all warning lights on and no regen braking. The car even freewheels when the gas peddle is released, instead of going into a regen slow down. Brought it to the dealer over a week ago. Fortunately I have the extended Toyota warranty, so everything is covered. I was told that it would be over $4500 to repair otherwise. A law suit certainly would have been filed. Basically the total failure mimicked the failure felt over the last 63,00o miles.

 

Since you cried wolf about the braking on bumpy road, can you still report to NHTSA the total failure?

 

Cried wolf? Are you nuts? Of course it has been reported again to the NHTSA. Are you a Toyota troll? There is now a recall to solve this very problem.

 

I own a 2010 prius III and ever since my purchase I've notice a braking issue with the Prius when it's those times any non-hybrid (lighter and heavier ones) would stop the brake completely give up for just a second or two. It's not normal ABS functions and in any other car I can in fact stop much harder (all three of my corollas included) It's easy to reproduce if going any speed and decelerating down a hill if i bump even the relief slits that are cut into the cement to prevent cracking that can be enough to make my brakes give up, (if not prepaired for the malfuction I garantee I would have rearended countless people so far) I drive 2 hours to work daily and my 2nd job is delivery driving in my prius.
So yes, other drivers experience this issue, either most are driving miss daisy or are in denial that it happens often)

 

Another note, when stopping on gravel it's a seperate feal, what I'm talking about is the brake suddenly letting to car roll free and having to mash the brake down to get it to reapply the brakes hard again

 

Bababooey was last seen:
Apr 9, 2012

 

Hate to tell everyone, but if you rear end another vehicle, it can sometimes be the fault of the other driver! I know this because I did rear end a vehicle years ago and the other driver was cited for not yielding the right-of-way when entering the roadway. I was not cited.

I also did have my Prius brakes 'lock up' the other day at low speed because my car slid 2-3 feet during a panic stop when another driver thought I had a Stop sign and pulled in front of me when I had the right-of-way.

 

i wood take it to the deeler.

 

I have a 2010 III. I'm not confident with the brake system in the Prius. Now I drive with more care and keep a big gap between the car in front of me. The car will skip if you braking when hitting a small bump or rough surface. Mostly due to the car changes the braking system from re-gen braking to the mechanical braking. There are that small moment that you feel the car skip before the mechanical brakes kick in. I don't see any issue with ABS. it kicks in when needed. but the brake system has it's issue.