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

Brakes issue: code C1252 and C1256

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Professorman, May 28, 2023.

  1. Professorman

    Professorman New Member

    Joined:
    May 28, 2023
    9
    3
    0
    Location:
    Hampton, VA
    Vehicle:
    2010 Prius
    Model:
    V
    I have a new to me 2010 Prius w/240k miles.
    I have a constant beeping, brake light on, and codes C1252 & C1256.

    My brake light came on and no longer working properly. Sometimes it works, sometimes it’s hard to press like manual braking, and sometimes it grabs when I’m pressing it hard. My regen is working.

    What can I start as my troubleshooting diagnostics?
     
  2. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,699
    48,946
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
  3. Professorman

    Professorman New Member

    Joined:
    May 28, 2023
    9
    3
    0
    Location:
    Hampton, VA
    Vehicle:
    2010 Prius
    Model:
    V
    Thank you. The diagnostics is very helpful. I am now pretty sure I need the brake master. I am testing if I need the pump as well.

    What are the pros and cons to buying used vs new?
    What other things do I need other than the parts? Do I need other gaskets?
    How much brake fluid do I need for the brake bleed process?

     
    bisco likes this.
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,699
    48,946
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    unfortunately, idk any more than you do, but i'm good at searching and learning.


    watch

    watch

    search


    many here have gone with salvage units. the difficulty is not being able to know if they are working, and tbh, they all have this problem, so at some point they are going to fail.
    hopefully, a new unit would be upgraded, so you have to decide which is best for you.
    there are tons of threads here with good advice:

    gen-3-known-brake-problem-outside-of-the-zjb-program-terms.235256
     
    Professorman likes this.
  5. Mr. F

    Mr. F Active Member

    Joined:
    Sep 21, 2020
    344
    195
    0
    Location:
    Texas
    Vehicle:
    2010 Prius
    Model:
    IV
    The possibility of introducing contaminants into the brake fluid.
     
    Professorman likes this.