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

Beeping at start up with All Brake Lights on?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by takadakeyo, Aug 17, 2022.

  1. takadakeyo

    takadakeyo Junior Member

    Joined:
    May 11, 2017
    3
    1
    0
    Location:
    Hawaii
    Vehicle:
    2014 Prius
    Model:
    II
    Greetings,
    My 2014 Prius has just around 115k miles and yesterday while driving home my ABS, Brake and Slip Indicator Lights came on for about 15secs, then went away.
    This morning when I went to turn on my car, my car would start up but start to beep and not stop. Also the ABS, Break and Slip Indicator lights are lite up. When I tried to idle, I also noticed my brakes weren't working. I would have to press really hard to break.

    I was wondering if anyone was familiar with this. I couldn't find a solution to this problem anywhere on here or google.

    No place where I live lets me rent a OBD scanner, and I was wondering if anyone knew what is happening, before I go out an buy a scanner to pull the error codes.
     
    #1 takadakeyo, Aug 17, 2022
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    8,026
    1,389
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    The expensive brake parts are kind of known to be somewhat problematic you will definitely be need to get in the codes because you're going to probably have a bunch of brake codes. That you will need to sort through and eliminate one by one.
     
    #2 Tombukt2, Aug 18, 2022
  3. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,239
    15,055
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    While there are around a couple hundred possible brake trouble codes, most of them only light the warning lights; only a handful of them also sound the alarm beep. Those are mostly the ones about the fluid pressure being too low to assist you with braking (which you can tell the car isn't just imagining, because you have to press really hard to brake).

    Usually when you come to the car in the morning to start, it has been sitting long enough for some fluid pressure to have bled off, and the pump has to run to replenish it. If the pressure had bled off low enough to sound the alarm, you'll get that beeping for some matter of seconds until the pump has pushed the pressure back up where it should be, and then the alarm and the lights go away, as you described in the first sentence.

    If the alarm and lights just stay on, then the pressure is never getting above the threshold. Either the pump is not running, or it is running but too worn to pump effectively, or it is pumping but there is an internal leak somewhere fast enough that the pump can't even overtake it.

    Reading the trouble codes will still get more details for the story, but the basic outlines are taking shape.
     
    #3 ChapmanF, Aug 18, 2022
(You must log in or sign up to post here.)