1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Catastrophic failure, no brakes at 50 MPH

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by skanex, Jul 16, 2014.

  1. nh7o

    nh7o Off grid since 1980

    Joined:
    Dec 10, 2011
    1,686
    337
    0
    Location:
    Hawaii
    Vehicle:
    2009 Prius
    Model:
    II
    The emergency brake supply can also run the accumulator pump a bit, not just the valves. It was removed in GenIII, so apparently not a compelling advantage to keep it.
     
  2. skanex

    skanex New Member

    Joined:
    Jul 16, 2014
    5
    1
    0
    Vehicle:
    2008 Prius
    Model:
    Two
    Hi all,

    So just to update, the issue was apparently a short in the 12v Aux battery and hey reviewed OP history and freeze frame data. The battery passed GR-8 but failed Under load. They replaced the battery and it seems to be running okay and I just have to wait to be reimbursed. Also apparently I was wrong: they did replace the pump when I was in for an oil change back in January. Based on your experience...does this seem like I'll be fine from here on out?

    Toyota corp said that if anything else happens they'll replace the DC Inverter free of charge as it's a part of the hybrid drive.
     
    ftl likes this.
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    i think your good and i would get that in writing.
     
  4. Former Member 68813

    Former Member 68813 Senior Member

    Joined:
    Oct 3, 2010
    3,524
    981
    8
    Location:
    US
    Vehicle:
    Other Hybrid
    Model:
    N/A
    #24 Former Member 68813, Aug 1, 2014
    Last edited: Aug 1, 2014
    edthefox5 likes this.
  5. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,039
    10,013
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    If 112 pounds (500 newtons) of brake pedal force was applied, and the underlying manual hydraulic brakes still did not work, then it is prima facie evidence of failure to meet federal passenger car braking regulations. It very much should be reported.
     
  6. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    If a dead 12 volt battery caused these issues the Prius would quickly become a pariah.
    Dead 12 volt batteries is what built this forum. Biggest thread maker here.

    And why is Toyota reimbursing you for anything?
     
  7. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,039
    10,013
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    If a simple dead 12V battery caused the brake system to fail completely, so even the underlying manual hydraulic system (without power boost) didn't work when the driver applied full body weight, then the design would flunk federal passenger car regulations. A recall would be mandated.

    There have been hints of possible problems in past threads, but not enough reports to form a critical mass to distinguish actual problems from operator errors.
     
    edthefox5 likes this.
  8. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    between u/a and no brakes, it's amazing they sell any.:rolleyes:
     
  9. taylor_priusII

    taylor_priusII New Member

    Joined:
    Jul 28, 2014
    17
    5
    0
    Location:
    Morton, IL
    Vehicle:
    2008 Prius
    Model:
    II
    It's official: these cars are death traps.
     
    edthefox5 likes this.
  10. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,039
    10,013
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Motor vehicles in general are death traps.

    The Prius is no worse than normal. In fact, with its IIHS Top Safety Pick rating, it is better than average.
     
    uart likes this.
  11. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    Using any machine that propels you has a risk of death, so its not fair to say that Prii are death traps. I am sure many on this site who have been in an accident would say otherwise.
     
  12. ftl

    ftl Explicator

    Joined:
    Jun 2, 2009
    1,812
    790
    0
    Location:
    Long Island NY
    Vehicle:
    2012 Prius c
    Model:
    Three
    See this thread, for example:
    New Prius C Crash | PriusChat
     
  13. GrumpyCabbie

    GrumpyCabbie Senior Member

    Joined:
    Dec 14, 2009
    6,722
    2,120
    45
    Location:
    North Yorkshire, UK
    Vehicle:
    2010 Prius
    Model:
    III
    Maybe Toyota US should use the softer brake discs and pads we have over here. Sure they don't last as long but they do work very well (even without regen).

    What do you want? Brakes that really bite and last 60,000 miles or brakes that are hard but last well over 100,000? I know which I'm happy with :)
     
  14. csoppe

    csoppe New Member

    Joined:
    Aug 22, 2014
    2
    0
    0
    Vehicle:
    2004 Prius
    Model:
    N/A
    I had the same issue happen on three occasions to my car (2004 Prius, about 114K miles on the car)! The last time it happened was on Monday, August 18, 2014. My car is in the shop right now and Toyota is scratching their heads after they thought they had fixed the issue on two other occasions (May 2014 and January 2013). Luckily no one was killed or hurt.

    Please shoot me an email at carol . soppe at gmail . com. I'd like to get your Toyota case number as Toyota is telling me that they haven't run into this problem with any other vehicle. Like you, I do not feel safe driving the car ever again and if this is part of a larger problem, they need to address it. Thanks!


     
  15. csoppe

    csoppe New Member

    Joined:
    Aug 22, 2014
    2
    0
    0
    Vehicle:
    2004 Prius
    Model:
    N/A
    Hi. Do you have a Toyota case number for when it happened to you? I've had this happen to me on three occasions over the last two years. They replaced the a computer chip the first time around (about $3K) and then checked all the wiring (they found rust on one of the wires and thought that was an issue). The third time just happened this week and Toyota is scratching their heads as if they have never seen this before.

    Of note, I did have the 12 volt battery replaced between the 2nd and 3rd time it happened. Be safe in your car! Based on my experience, I think it could happen again.

     
  16. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,039
    10,013
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    ^^ Did you put your full body weight into the brake pedal, or at least 112 pounds (500 newtons metric?) If so, and the brakes still didn't work like old fashioned manual (no power assist) brakes, then this would be evidence of failure to meet federal passenger car braking requirements. Proven failure would force a recall.

    But even at lower pedal forces, it could point to a potential serious problem.
    Any evidence pointing to such problems needs to be documented here:
    NHTSA: File a Vehicle Safety Complaint
     
  17. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    what if you only weigh 111?
     
    orenji likes this.
  18. fuzzy1

    fuzzy1 Senior Member

    Joined:
    Feb 26, 2009
    17,039
    10,013
    90
    Location:
    Western Washington
    Vehicle:
    Other Hybrid
    Model:
    N/A
    Most people can brace against the seat well enough to press with considerably more force than their body weight.
     
  19. orenji

    orenji Senior Member

    Joined:
    Aug 17, 2013
    5,884
    3,486
    0
    Vehicle:
    2010 Prius
    Model:
    Three
    Fat is good!
     
    milkman44 likes this.
  20. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    fat, is where it's at.