Brake failure

Why do you say you're not the first? I've not heard of this before.

The dealer should be able to figure out what's wrong with the stored codes. Make them escalate the problem to the regional Toyota people if necessary; it isn't something trivial.

 

<div class='quotetop'>QUOTE(nicks @ May 10 2007, 02:34 PM) [snapback]439314[/snapback]</div>

Nick,

I'm another "Old-Timer" (2004 with 85,000 miles) and had never seen a brake problem of this nature discussed in any Prius droup. Report the codes here and one of the Guru's may be able to identify the source of the problem. In case of a re-occurrence, remember that you have an emergency brake and it is an old fashioned, reliable, mechanical linkage.

One point, below 7 MPH the system uses only the friction brakes, regeneration is used to slow the car at higher speeds.

JeffD

 

<div class='quotetop'>QUOTE(nicks @ May 10 2007, 04:05 PM) [snapback]439425[/snapback]</div>

Please provide links or references

 

what codes were generated? can't help much without them. dealer should not have let your car leave their property. if it happens again and you hit something, you've got a lawsuit, easy.

either go back or find another dealer to take care of this. and get those codes, we may be able to help ya out.

 

I recall another case where someone complained of brake failure, codes were stored, and the dealer said the system was fine. SOmething about an "accumulator" was mentioned.

Several posters recommended pushing the issue all the way up the Toyota chain. It's a safety thing.

Hope it never happens to me.

 

This is the first I've heard of it also. Please provide links to the posts you've seen if possible and please keep up updated on what happens with your car.

 

<div class='quotetop'>QUOTE(nicks @ May 10 2007, 02:34 PM) [snapback]439314[/snapback]</div>

please help us help you.... answer the following questions.

What buzzer and what warning light ?

Road conditions ? (dry,wet,gravel, sand, raining)

What speed were you driving ?

You say you had to pump the brake....was the pedal going to the floor before you pumped?


Are you aware that if you are applying brakes and drive over a pot hole that could trigger the ABS system and you will feel the brakes stop working for a second or 2 ?
(this would not generat error codes.... but you might have had error codes before this happened but no one checked for them before.)

Note: you can over ride the ABS by applying more pressure on the brake.(no need to pump)

 

It would be useful to know which "buzzer" you heard in this case,
because the braking system actually has its own warning beeper that
issues a loud, high-pitched scream if the brake system can't build
reserve pressure or something else goes wrong with the hydraulics.
You can reproduce that by pulling the "ABS MTR" and "ABS MTR 2"
blue relays out of the block under the hood, and then pumping the
pedal a few times. [Pulling those, in fact, is a safety procedure
to do before doing any brake work.] It was either that, and/or the
normal beeper that goes on when, for example, you open the drivers
door while you're in Drive or Neutral.
.
The pot-hole issue isn't really ABS, it's the regenerative system
giving up. See this for much more info.
.
_H*

 

<div class='quotetop'>QUOTE(hobbit @ May 11 2007, 08:10 AM) [snapback]439788[/snapback]</div>

No, I am talking about the ABS cutting in because the wheels bounced up off the road as you were stopping.
This happens with alot of cars not just prius.

Here is a link to another reported brake failure and they also talk about the ABS cutting in.

http://priuschat.com/index.php?showtopic=12393&hl=

 

I've noticed that when the ABS kicks in, it DOES feel like I wont stop. And yes, warning lights do start flashing. Perhaps this is a case of the ABS kicking in accidentally or something?

 

Weird...

Hasn't happened since?

 

That is scary, I hope the someone can document what these error codes mean? Did the dealer say what these codes mean?

 

Hmm. *That* sounds like you're out of brake fluid. The system
*does* use hydraulic pressure as the signal input to braking in
general, including regen.
.
Oh, now wait a sec, you said "high pitched squeal". Guess what,
that's the little alarm beeper box attached to the brake system,
mounted under the dash above the pedals. That goes off if you've
lost brake pressure, for whatever reason -- either the accumulator
pump not running, lack of fluid, etc etc. Are you familiar with
the sound of the pump building brake pressure [almost every prius
driver is]? Do you hear it if you press and hold the pedal a couple
of times? Is the fluid reservoir over near the right-hand strut
tower filled properly?
.
P0A0F is sort of one of those generic "engine failed to start", but
issued by the hybrid controller. C1300 is more relevant, "skid
control ECU failure" which doesn't really spell out *what* it
thinks the problem is, but who knows, there could be a replacement
ECU in your future. The real question is, did it fix itself in
the meantime, and did Toyota perhaps do something they don't even
know about to set it right, such as reseat connectors, etc?
.
_H*

 

that alarm goes off when the actuator loses pressure in the brake system. but the skid control ecu could be telling the actuator to not keep pressure. those should be thoroughly investigated.

basically, when the electronic system fails, you revert to hydraulic- front brakes only, no power assist. in heavy traffic you could easily hit someone.

refuse to take the car back from the dealership until they have done something about it. this is not a safe condition for you to be driving.