Gen 4 Brake Failure

Did you get warning lights on the dash, and/or "check hybrid system" warning? Did you by chance have anything plugged into the OBD port?

There is a condition, if the car has some sort of communication failure, it'll put the brakes into a sort of default mode. They still "work" but it more like "work to rule". First impression, especially braking on a downhill I would think, is they aren't working. But push harder and they do work, but it's taking greater effort, and they don't feel linear/modulated.

FWIW, I had what I describe happen several times, while a was using a ScanGauge II, plugged into OBD port. Quit using on advice of dealership, as a test, and it never happened again. On a 3rd gen, if it matters.

 

Imho, it sounds like a good idea to give a lawyer who specializes in Oregon auto law a call.

 

Defective car and dealership foot-dragging aside, that’s life threatening. Make a report to US automotive safety organization (unclear on who that is).

 

NHTSA. Start here:

Report a Safety Problem

 

is the state consumer affairs office worth a call?

 

I’d suggest consulting a lawyer, as @prius16 kindly suggested above, before making any official complaints.

As much as it’s desirable for incidents such as this to be reported to the authorities, forbearing from anything that might inconvenience the dealer or manufacturer could well be a bargaining chip—and if you do choose to make a complaint, it should be written in a way that wouldn’t risk compromising other proceedings.

 

Summary:
Toyota and the NHTSA know *EXACTLY* what happened.

They know at least the following:
o Speed of vehicle before the brake pedal was activated
o For the whole time, the amount of force, and travel of the brake pedal.
o For the whole time, the speed of each wheel.
o The amount of regen requested (Hybrid thing).
o The amount of regen obtained (Hybrid thing).
o The amount of brake pressure requested (Hybrid thing).
o The amount of brake pressure obtained (Hybrid thing).
o Amount, and direction, of the force of impact (A gen4 Prius, and other Toyota thing).
o The GPS locations from the start of the brake pedal, to the complete stop.
o And, other telemetry data.

Also, ALL of the above, plus much more, was very likely sent to directly Toyota within seconds of the impact (by the 4G antenna on your car). If you don't like that, then buy a car from the 70's.

Fwiw, unless things have changed, for Toyota, Toyota corporate has to approve, and issue a code, for the Dealer retrieval of Black Box data, before the Black Box data can even be accessed by the Toyota scan tool. Toyota corporate will also exactly specify, who/what-entities can see the data. Note, it's a crime (corporate proprietary information) for a non-approved person/entity, to access, or see that data.


So, again, strongly consider Lawyering up.
NOTES:
1) Many people honestly think they had the brakes on, but telemetry data often shows much different.
Fwiw, until mandated, Black Box data was done, and collected, to protect the manufacturer against law suits.
And, improper warranty claims. No, you can not track your Prius, then complain about engine/tranny/suspension/etc warranty issues. Fwiw, of course, that is much more likely on (real)Sports Cars.

2) Depending on your State laws, if it was in fact an malfunction, you can request a refund, or a replacement vehicle, and may be able to sue for additional monies (you would likely need to sue, to at least get the lawyers fees back).
Or, like with Michigan State laws, you're entitled to have the vehicle fixed by Toyota, and if you had 2 more "serious" failures within one year of buying the car (a semi-BS lemon law), you would be entitled to a refund (if requested) for the return of the vehicle.


The only way you may be able to get some info on the Toyota black box data, is through a lawyer (But, don't bet on it).
Or, if the information comes up in a court case, against you, for civil, or criminal chargers. (imho, then, that clearly would not be good).


I very strongly suggest that you spend at least an hour doing google searches on Toyota black box data recording.

Also consider, depending on the exact circumstances, all of the above that you posted, could be considered libel, and you could be sued out of existence. Tesla does that in a heartbeat.

Fwiw, other than for appropriate Federal requests, or in response to a potential safety/recall issue (like brakes failing), Toyota very rarely pulls Black Box info from the car.
However, some amount of data is still sent back to Toyota (by 4G), when a "crash/accident/incident" has been detected by the air-bag/force senors.
Again, if someone does not like the above, then buy a car from the 70's. Or, a pre-'94 Mustang. I forget when Ford started adding black box info, in their various cars/trucks. GM was pretty early on many vehicles.

Good Luck!

 

I was able to retrieve Vehicle Control History data from my car with an ordinary Toyota Techstream diagnostic system. Data for actual collisions is stored separately in the same event data recorder (EDR) and can be retrieved using the Bosch CDR readout device, which is available to anyone with $7,400.

I’m not sure Toyota’s EDRs actually record braking force or brake pedal travel. The last time this came up, the readout from a 12EDR didn’t include those data, just whether the stop light was on or off, and I think that may also be true of later models. The “Record Data Item Chart” in the Repair Manual (more info), under Vehicle Interior: Supplemental Restraint Systems: Airbag System: Vehicle Control History: 2021 - 2022 MY Prius, lists—among more than 250 other items—“Brake SW” (either “ON” or “OFF”) and “Brake Oil Pressure” (“Brake fluid pressure inside master cylinder”) but not brake pedal angle.

 

Cool, thanks!

I wonder how much "Toyota only" data there is?
Tesla is well known for their Tesla-only data, for crashes/events.

I don't follow, nor stay up to date, with Toyota scan tools.
I bought my Prius, as a reliable, functional car, that required minimal/no maintenance/repair (from me). Another reason, I bought the 10 year Toyota extended warranty. $2K for 10years/100K miles.
So, for $200/year, for 10 years, while I sit on my rear-end, while Toyota fixes any issues.
YES!


I have 3 car "toys", that I play with, and will/can/have torn down to the lowest level.

Imho, my Prius gets body braces/etc, to help stiffen up the frame, to near/better than Lexus level. Better ride, handling, and frame life. That's about it.
And, of course, the required front-dash/rear cam, in case some idiot on a cell phone crashes into my new month old $100K F150 EV Lighting. Oops, I mean Prius.

Code:

https://www.youtube.com/watch?v=tpjX8XC1d1Y
I wrecked my New F-150 Lightning! Here is how it held up!
Drive Electric
Nov 22, 2022
I wrecked my Brand New F-150 Lightning and this is what happened!

Heck, I can't even put a tow hitch on my Prius, (for a bike carrier/etc), since it would/could invalidate a very large portion of my 10 year extended warranty.
Btw, for Sports car, any track use, can invalidate the whole warranty! So, with GPS tracking, and performance/use monitoring, new sports cars are not a great choice for tracking, and hoping for any warranty coverage - even for glove box light. Ford and GM started doing that in the 90's.

 

I'd expect those two to be mighty closely correlated.

 

That’s usually true, but times when it might not be are among the most interesting. Considering how many other values are saved, I wonder why the designers didn’t include the output voltages from the stroke sensors, which measure pedal angle more directly.

It might be useful to distinguish between active safety systems, such as the pre-collision system in Toyota Safety Sense 2.0 (TSS 2.0), and the electronically controlled brake system.

At the present state of the art, TSS 2.0 and similar systems aren’t designed to work in all situations, because of limits of sensor and processing technology and to reduce the risk of false activation, which itself could be very dangerous. The system’s effectiveness is judged statistically, by the reduction in overall frequency and severity of collisions involving equipped vehicles, not by whether it worked on any particular occasion. The Owner’s Manual (PDF) discloses these limitations; see the warnings on pages 282 and 293, where Toyota writes, “This system will not prevent collisions or lessen collision damage or injury in every situation,” and the long list of “Situations in which the system may not operate properly,” pages 299–301.

In contrast, the electronically controlled brake system is designed to provide braking force on demand by the driver, when requested by the pre-collision system, and in some other circumstances, with very high reliability. The braking response might sometimes be more (as with Brake Assist) or less (as with ABS) than usual, but it shouldn’t ever happen that you press the brake pedal and get no braking. If that happened, by definition, something went wrong, even if the skid control ECU (the computer that controls the system) didn’t detect a malfunction or store a diagnostic trouble code (DTC).

Setting aside the legalities, if a brake-related incident occurred with my car, in addition to checking for DTCs and inspecting for physical signs of a problem (low brake fluid level, contaminated brake fluid, evidence of leaks, abnormal sounds, etc.), I’d retrieve any related vehicle control history or collision events and go over the data very carefully, looking for inconsistencies that might indicate a malfunction. A limitation of this method, of course, is that many of the recorded data come from the same computers that control the system, and in principle, the same malfunction might cause both improper operation and storage of inaccurate data. I don’t mean to imply that this happened in your incident, only that it’s a possibility to keep in mind.

 

Sorry to hear about this; but just because there are no error codes - doesn't mean there isn't a problem. It just means that the computer(s) didn't see a problem.

Kudos; for having enough sense to use your parking brakes to slow-down your car. I have to ask; did you just "stand" on your brake pedal or did you try pumping-it. The reason I ask is because there is a mechanical and electrical portion to your braking system. If the electrical portion portion of your braking system fails - your mechanical system should allow you to slow-down and stop the car at much greater distances (loss of power brake / brake booster function). Old braking systems utilized engine vacuum pressure.

I've actually had a brake booster fail on a late 2000 VW Jetta. Because of German engineering, when I touched the brake pedal - all four wheels locked-up. I almost got rear-ended; and a very nasty stare from the driver of the car behind me as he passed. That's when the brake lamp lit-up and stayed lit.Every-time I touched the brake pedal; all four wheels would lock-up. Since the dealer could duplicate the issue; It was fixed for free - even though I was out of warranty. There may have been a TSB out on it, but I never checked - It was a free repair.

 

Wow, that's a scary story! It almost sounds like the car turned itself off, causing brake and collision-avoidance systems to fail! Smart to get rid of it, I wouldn't trust it, either.