near complete brake failure on my way home from Coachella

Toyota has no obligation to pay for the repair. The warranty is up. Would it be nice if they did? Sure. For anyone who thinks that any part on any car should last the lifetime of the car, your crazy. These cars, just like any other car, is mechanical and parts will fail. I can only remember this happening one other time with the brakes. Hardly constitutes a design flaw.

For all those that think extended warranties are a waste, this is one repair that would have paid for itself three times over. Alot of people balk at the extended warranties, but then apparently think Toyota should somehow pay for repairs out of the warranty period. It is known that these cars have a 36k mile warranty. Why should it be expected for Toyota to pay for repairs after this period?

 

A power loss fails over to fail-safe automatically but in other failure modes, I expect the ECU to be an active part of the fail-safe switchover.

Given that the system is designed to fail safely in a total power loss, the presence of the capacitor backup for temporary power is another level of protection added. I disagree with your usage of the word redundancy. Strictly speaking, there is no redundant system since every component is used actively in normal operation. In traditional cars, there's partial redundancy for braking using the parking drums or the engine, in the case of primary system failure.

 

First, I'm glad no one was hurt. Second, I don't think anyone should rail on deltron for not being more cautious because:
1. I have done my own wrenching since high school. If I heard a squeaking as described by deltron, my first instinct would be that it is the spring built in to many brakes to warn you that the pads are excessively worn. Many cars use a combination of this spring coupled with an electrical sensor (wear wire, contact, etc) so even if there is a problem with the electrical sensor, the squealing will warn you. It would NOT make me think that it's something IMPERATIVE since in most systems it's letting you know before the pads become absolutely unusable.

2. Many times intermittent situations occur so quickly that you don't have time sit there and make critical decisions. "Oh, all the lights are on/flashing. Let me get my camera so I can get a good picture of my dash to analyze what's going on." It was an intermittent situation that probably lasted a few seconds at most, then went back to "normal." From what I read, it left no residual info (warning light still lit, fault code, etc).

I myself, in the same situation, would think I would need to get it checked out, but with the lack of anything showing something eminent (CEL, fault code, etc), I would assume that I could check it out/take it to a shop the next day/when I got home/etc.

With that said, part failures do happen, they happen at 5 miles, and they happen at 200,000 miles. There is no way for ALL parts in ANYTHING to last "at least" xxx miles. There will ALWAYS be periodic failure of parts that are SUPPOSED to last x miles, x years, etc.

It seems, at least for now, that this is at least an unusual occurrence as there are many members here, and I did not see anyone else saying they had the same experience, and I have never heard of such failure in a Gen III even outside this board.

I would chalk it up to an unfortunate failure of a part that occurred outside of the warranty period - which can happen to ANY part in ANY car.

I hope that such a potentially catastrophic failure is taken care of by Toyota on a good faith basis, but I wouldn't depend on it.

Of greater concern is that if what happened the day before IS connected to the brake failure, the system somehow did "see" it, but did NOT throw any permanent warning such as an indicator light or fault code. Such a dangerous failure, if foreseen by the system SHOULD have thrown a code, set a warning indicator, etc.

 

I forgot to include in my post:

Even if the events of the day before did not have anything to do with the brake failure, I would think that with the Prius sophistication that when the brake failure DID occur, such a dangerous/potentially catastrophic failure should have created or caused a warning light or fault code/cel at that moment if not at any other time.

 

wow, I cannot wait to here what happens with this situation...

glad you are ok, hope they cover it.

 

Scary. I am glad that you were able to avoid an accident. Hope you figure this out soon.

 

Wow, lot of twists and turns in this case

* Very abnormal brake response which you correctly reported to NHTSA. Good job

* You nearly had an accident due to something that was clearly not your fault

* The car did give a prior warning, but you drove it. Works against you a bit, but you know that

* The quoted $3k repair cost is prohibitive and ridiculous. The car is to be cost effective, not a financial burden.

* I'll be interested to see how this turns out

 

How could a braking system such as you describe possibly meet federal motor vehicle safety standards for hydraulic and electric brake systems?

I don't believe that one could, which is why your brake-by-wire description is being labeled as FUD.

I am not passing any judgement on Deltron's case. A few other posters have described cases where the brake pedal 'fell to the floor' as if the brake-by-wire system shut down. But it appears that the underlying backup manual hydraulic system -- which tpfun says doesn't exist -- still worked, albeit with pedal forces outside the range that modern power brake users normally expect. I strongly hope that Toyota puts serious effort into failure analysis to make sure that existing single-fault incidents are all protected and do not occur at higher than expected rates, to ensure that unprotected multiple-fault incidents almost never happen.

 

I've no idea whether the guv bureaucrats are ahead of the curve or behind here.

Every actuator including the one which enables the fail safe bypass is controlled directly by the ECU. There is no electrical component which takes over in the event of main systems failure, thus there's no redundancy. When the ECU detects a failure, it decides to go into fail safe mode and sends out the required electrical signals. This is not another Prius bashing statement since it applies to other such vehicles of this nature as well.

As I said above, contrast this with a traditional vehicle where additional stopping power can be derived from the engine by manually downshifting and using the parking brake ...

 

IMHO the brake-by-wire systems should comply the same regulations as pneumatic brakes on trucks. aka if they fail, they engage

 

Me too.

The biggest thing to me is a part failed that had no business failing at anything less than 150,000 miles, especially with a 3k replacement price tag! I once replaced a brake master cylinder on an old van for less than 100 bucks. Warranty on a part like this should be more than 36,000 miles and it's not a good sign that this happened to someone with so few miles. As a 2010 Prius owner approaching 30,000 miles this makes me feel uneasy, combined with the engine knocking problem. I wonder if this part has failed or will fail on any other 2010 Prius's before 100,000 miles? I thought things like this weren't supposed to happen to Toyota's.

 

Do you actually read the stuff that you link to as supporting documentation ? Those rules and regulations are not applicable to the Prius unless you are referring to the 2013 Prius XXXL model.

quote: This standard applies to multi-purpose passenger vehicles, trucks, and buses with a GVWR greater than 3,500 kilograms (7,716 pounds) that are equipped with hydraulic or electric brake systems.

 

scarry news not normal i whould never have considered a car that needs a 3k$ brake job for a taxi !!!!! hope for the best and expect the worst????????????

 

The Prius can be downshifted to B for additional engine braking. Why can't the parking brake be used on the Prius?

 

From the Toyota Service Manual:

BC: Brake Control

 

Sorry. During the Toyota SUA/Braking fiasco over a year ago, I read some DOT brake regulations that clearly contradicted your claims. Apparently in the rush to locate it this week, I grabbed the wrong section.

Try this: Standard No. 135; Light vehicle brake systems. - Federal Motor Carrier Safety Administration

some snippets:
...
S3. Application. This standard applies to passenger cars manufactured on or after September 1, 2000 and to multi-purpose passenger vehicles, trucks and buses with a gross vehicle weight rating (GVWR) of 3,500 kilograms (7,716 pounds) or less, manufactured on or after September 1, 2002. In addition, at the option of the manufacturer, passenger cars manufactured before September 1, 2000, and multi-purpose passenger vehicles, trucks and buses with a GVWR of 3,500 kilograms (7,716 pounds) or less, manufactured before September 1, 2002, may meet the requirements of this standard instead of Federal Motor Vehicle No. 105, Hydraulic Brake Systems.

...
S7.10. Hydraulic circuit failure.
...
S7.10.3. ... (f) Alter the service brake system to produce any single failure. For a hydraulic circuit, this may be any single rupture or leakage type failure, other than a structural failure of a housing that is common to two or more subsystems. For a vehicle in which the brake signal is transmitted electrically between the brake pedal and some or all of the foundation brakes, regardless of the means of actuation of the foundation brakes, this may be any single failure in any circuit that electrically transmits the brake signal. ...

S7.10.4 Performance requirements. For vehicles manufactured with a split service brake system, in the event of any failure in a single subsystem, as specified in S7.10.3(f) of this standard, and after activation of the brake system indicator as specified in S5.5.1, the remaining portions of the service brake system shall continue to operate and shall stop the vehicle as specified in S7.10.4(a) or S7.10.4(b). For vehicles not manufactured with a split service brake system, in the event of any failure in any component of the service brake system, as specified in S7.10.3(f), and after activation of the brake system indicator as specified in S5.5.1 of this standard, the vehicle shall, by operation of the service brake control, stop 10 times consecutively as specified in S7.10.4(a) or S7.10.4(b).

The performance standard for any single subsystem or component failure is the same as for total power loss: At 62.1 mph, with a pedal for of 112.4 pounds, the stopping distance must be 551 feet or less (metric units translated to Imperial.)

 

Another blind, knee jerk Toyota apologist.

 

Anytime a thread has at least two trolls, better to stay away and let the thread die a natural death.