Any test for Brake Pedal Stroke Sensor?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by turbo5spd-prius, Mar 1, 2025 at 3:47 PM.

  1. turbo5spd-prius

    turbo5spd-prius Junior Member

    Joined:
    Aug 27, 2023
    60
    14
    0
    Location:
    United States
    Vehicle:
    2005 Prius
    Model:
    Two
    Is there a way to test the brake pedal stroke sensor? I.e. a way to test it outside the car. My original one gave problems. I tried a used one from E Bay and it does the same, though mine's smooth and the used one is detented.
     
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    11,088
    1,931
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    This is the piece that's actually connected to the pedal? I don't think detented is correct but I'm not positive of that but I would think so If this is the piece that's connected to the pedal it feeds the pressure back to the actuator which is an almost the middle of the car on the firewall it's like the brake master cylinder on the older Corolla.
     
  3. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
    3,851
    1,852
    0
    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    What are your symptoms? Any trouble codes?

    From the test descriptions, the sensor has a V-reference power supply, ground, and dual outputs that change voltage.

    It could be a simple variable resistance sensor, or it could be variable output hall effect sensor.

    Posted via the PriusChat mobile app.
     
  4. turbo5spd-prius

    turbo5spd-prius Junior Member

    Joined:
    Aug 27, 2023
    60
    14
    0
    Location:
    United States
    Vehicle:
    2005 Prius
    Model:
    Two
    Yep, it's connected to the pedal with the spring loaded arm. I say "detented" for the used one because it's not smooth when you move that arm but you can feel it "tick" lightly through its arc.
     
  5. turbo5spd-prius

    turbo5spd-prius Junior Member

    Joined:
    Aug 27, 2023
    60
    14
    0
    Location:
    United States
    Vehicle:
    2005 Prius
    Model:
    Two
    I get the ((!)) light on the dash and the code that indicates a brake pedal stroke sensor fault (don't remember the code). It seems to only affect the braking phase near the end as the car comes to a stop. You can feel the brakes sort of grab and let go quickly. Since it's almost stopped, the feeling isn't strong and it's really more the sound you notice. If you're not listening for it, you won't ever notice.
     
  6. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    11,088
    1,931
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    No I remember this very well when my break actuator was failing I replaced it all that went away as far as I know the stroke sensor or the part that's connected to the pedal it doesn't have any electronics does it isn't it all just hydraulic I don't have one out to put in my hand so if that's the case then it's measuring the stroke or the push of the brake fluid inside of the actuator because when you step on this thing connected to your pedal it pushes fluid over to the actuator I do believe and then pretty much the computer takes over so if you push on the pedal and it doesn't move the amount of fluid expected or something along those lines I guess you would get a code for the stroke business I guess. If you have this out in your hand doesn't this look kind of like a regular master cylinder from a Corolla or a Yaris no electrical plugs it's hydraulic fittings and where the fitting connects to the pedal that pushes on the hydraulics that should be rebuildable It might even be stamped on the side of it 7/8 or 3/4 some metric equivalent That's the bore size of the hydraulic piece that goes up and down in that hole It's kind of like the inside of a rear wheel cylinder. I would think you'd want that thing to be operating smoothly and moving a good shot of fluid every time you compress it If not pull the boot remove the snap ring or the wound ring pull the guts out and have a look If it's 3/4 or 7/8 bore there should be all kinds of options for the rubber parts
     
  7. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,987
    4,045
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    Reporting the code, rather than than text, is important.

    People using an inadequate scan tool (read cheap, limited) often report P1121 as "Accelerator Pedal Position Sensor Error, Performance/Range". On another car, even a Toyota P1121 might mean that, but on a Pruis it does not. It means that the coolant flow control valve position sensor circuit is stuck.

    It might be in your best interests to remember that code or do a rescan.
     
    MAX2 likes this.
  8. turbo5spd-prius

    turbo5spd-prius Junior Member

    Joined:
    Aug 27, 2023
    60
    14
    0
    Location:
    United States
    Vehicle:
    2005 Prius
    Model:
    Two
    Here is the sensor.

    I'll rescan tomorrow but looking at my old generic system screenshots, I'm sure the error code is C1207. I use techstream.
     
  9. dolj

    dolj Senior Member

    Joined:
    May 14, 2012
    7,987
    4,045
    0
    Location:
    Wellington, New Zealand
    Vehicle:
    2007 Prius
    Model:
    N/A
    C1207 is not found in the 2006 manual.
     
  10. turbo5spd-prius

    turbo5spd-prius Junior Member

    Joined:
    Aug 27, 2023
    60
    14
    0
    Location:
    United States
    Vehicle:
    2005 Prius
    Model:
    Two
    Sorry, C1247.

    My laptop keyboard is wonky so I mistyped it.