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

2001 Prius, 220k C1246

Discussion in 'Generation 1 Prius Discussion' started by mohater, Oct 25, 2023.

  1. mohater

    mohater Junior Member

    Joined:
    Jul 10, 2015
    51
    19
    0
    Location:
    Fremont CA
    Vehicle:
    2008 Prius
    Model:
    Four
    Hi Folks,

    Thanks again for all the prior help.

    Working on a 2001 Prius this time for the non profit. Has a perpetual C1246 code. There is a C1214 that comes and goes (brake light comes and goes with C1214)

    Code has been there as long as the non profit has had the car (over three years now, used as a loaner vehicle for clients. Vehicle being prepped to be given away to an eligible client next). We have put ~20k on the car in the three years, never a single issue with the brakes (outside of the perpetual ABS light on and the C1246 code)

    I looked at other threads where brakes are acting up, flashing ABS, etc and the C1254 was indicated the brake motor was failing. Not sure if that's the case here, but willing to go get one out at the junkyard if that's the path forward.

    TIA
     
  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    10,384
    1,794
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    I don't know the old one that well but does the pump seem to run all the time?
     
    mohater likes this.
  3. mohater

    mohater Junior Member

    Joined:
    Jul 10, 2015
    51
    19
    0
    Location:
    Fremont CA
    Vehicle:
    2008 Prius
    Model:
    Four
    No, the pump isn't always running.
     
  4. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    24,912
    16,215
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    C1246 is a code about the master cylinder pressure sensor. That would be located in the brake actuator.

    In Gen 1, the brake system components were widely separated. There's a master cylinder on the firewall right where you'd expect a master cylinder to be, the pump/accumulator assembly is at the other end of the firewall, and the actuator is on the firewall amidships, between those other two. The ECU is inside the cabin.

    As with any code about a sensor, the problem can turn out to be elsewhere, like in wiring or connectors on the way to the sensor. The five pages for that code in the repair manual suggest steps for pinning down the cause.

    Toyota Service Information and Where To Find It | PriusChat
     
    mohater likes this.
  5. mohater

    mohater Junior Member

    Joined:
    Jul 10, 2015
    51
    19
    0
    Location:
    Fremont CA
    Vehicle:
    2008 Prius
    Model:
    Four
    Thanks, will start investigating.