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

brakes fail to engage when I put my car into gear

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by michelle hoisch, Apr 12, 2013.

  1. michelle hoisch

    michelle hoisch New Member

    Joined:
    Apr 12, 2013
    3
    0
    0
    Vehicle:
    2004 Prius
    Model:
    N/A
    I have taken my 2004 Pruis into the Toyota dealership and have been told that there is nothing wrong with my car and it is safe to drive. Here is what is happening.

    Sometimes when I start my car and put the car into gear, which you are not supposed to be able to do without your foot on the brake, the car will start rolling before I take my foot off of the brake. I am on level ground when this happens, and I am positive I have my foot firmly on the brake. My first inclination is to push harder on the brake, which does nothing. If I take my foot off of the brake and then reapply it, then the brakes will work and the car will stop.

    After this happened a few times, I started paying more careful attention. Whenever this happens, the ABS light is on. When I take my foot off of the brake, the ABS light goes off, and as I said, the brakes work normally.

    Furthermore, this only happens if I have been sitting in my parked car for a few minutes with the engine off. It does not happen if I am getting into the car after being away for a few minutes, it only happens if I sit in the car for a few minutes and then turn the car back on to go somewhere.

    This is, of course, not only irritating, but unsafe. It can be easy, if you are distracted, to have the car roll into someone or something if you are looking away, thinking that even though you put the car into gear, it will not go anywhere because it is not supposed to go anywhere, you have your foot on the brake!!!!

    Like I said, Toyota has looked at this a bunch of times and tells me nothing is wrong. I am beyond frustrated.
     
    #1 michelle hoisch, Apr 12, 2013
  2. nh7o

    nh7o Off grid since 1980

    Joined:
    Dec 10, 2011
    1,686
    340
    0
    Location:
    Hawaii
    Vehicle:
    2009 Prius
    Model:
    II
    Most strange problems like this on PC require first to check the 12V battery. When was it last replaced? Toyota does not know, more often than not, how to test if the12V battery is still good. Read this, and let us know what numbers you find:
    Entering Maintenance Mode (aka 12V Battery Check) without Switching Headlights ON/OFF | PriusChat

    I could imagine your symptoms happening if the 12V was not up to snuff. When you step on the brake pedal, the brake pressure pump, which is 12V operated, runs briefly. If the pump does not create proper pressure in the system, the ABS light will come on, and the brakes may not hold the car. Pump the brakes again, and the problem may go away.

    The other alternative is the brake pressure pump itself (a.k.a. actuator) is going. Somehow it will be necessary to read the ABS codes while the light is on to really find out what is going on.
     
    #2 nh7o, Apr 13, 2013
  3. michelle hoisch

    michelle hoisch New Member

    Joined:
    Apr 12, 2013
    3
    0
    0
    Vehicle:
    2004 Prius
    Model:
    N/A
     
    #3 michelle hoisch, Apr 13, 2013
  4. michelle hoisch

    michelle hoisch New Member

    Joined:
    Apr 12, 2013
    3
    0
    0
    Vehicle:
    2004 Prius
    Model:
    N/A
    well that is interesting because this has been going on for several years, and one mechanic did say the 12 volt battery needed to be replaced, and replaced it. The problem did not go away. I will try the 12 volt battery check, but if the battery was properly replaced, I am going to say maybe the actuator is the problem. But I have been having this problem for 3 years (I cannot believe I am saying this, because it is unbelievable that I have put up with it for three years!!!) and if it was a bad actuator or brake pump, wouldn't something bitter have started happening?
     
    #4 michelle hoisch, Apr 13, 2013
  5. RAL

    RAL Member

    Joined:
    Mar 2, 2013
    66
    34
    0
    Vehicle:
    2012 Prius
    Model:
    Three
    Go to a different dealer. This is a subtle electrical glitch that could have far from minor consequences. Don't put this off, brakes are the last item to wait and see on!!


    RAL
     
    #5 RAL, Apr 13, 2013
  6. nh7o

    nh7o Off grid since 1980

    Joined:
    Dec 10, 2011
    1,686
    340
    0
    Location:
    Hawaii
    Vehicle:
    2009 Prius
    Model:
    II
    If you can reproduce the problem for the dealer, and the warning light is on, then you can get the codes read. This is really the first and most crucial step to getting it solved.
     
    #6 nh7o, Apr 13, 2013
(You must log in or sign up to post here.)