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Brake Accumulator Not Getting Power ... Constant 12Volts

Discussion in 'Prius c Technical Discussion' started by striver, Dec 26, 2020.

  1. striver

    striver Junior Member

    Joined:
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    Location:
    trinidad & tibago
    Vehicle:
    2014 Aqua
    Model:
    N/A
    Hello I'm working on a 2013 Prius C. All brake warning lights are on

    Code C1256.. low accumulator brake pressure

    All fuses are good

    I'm not getting constant 12 Volts to the accumulator connector I'm actually getting 1.76Volts

    The pump is not being turned on and hence not pressurizing the system and throwing this code

    My question is can anyone here provide a repair manual for this vehicle or guide me next where to check for this drop in voltage or signal.


    does the skid control ecu command this circuit?


    20201221_083952.jpg
     
    #1 striver, Dec 26, 2020
  2. ChapmanF

    ChapmanF Senior Member

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    This wiki page has information on access to the Repair Manual and the Electrical Wiring Diagram. In the US, we would go to techinfo.toyota.com. I am not sure of the right destination for Trinidad and Tobago. (If the car was imported from another market, it might work best to use the Toyota site for the origin market.)

    According to my (US) Gen 3 liftback manuals, the accumulator should have two ground wires (white with black stripe) and two +12 supply wires (solid black), and these come directly from the skid ECU, which is integral with the master cylinder/actuator, and the relays are inside it. Power supplying those relays comes from ABS MTR 1 and ABS MTR 2 fuses.

    But I don't know how much of that carries over to the c.
     
    #2 ChapmanF, Dec 27, 2020
  3. striver

    striver Junior Member

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    thank you for the info. I checked the wires and they do come from the abs booster aka brake ecu etc

    im suspecting the booster as an issue here now



    20201228_080916.jpg 20201228_082458.jpg 20201228_082455.jpg
     
    #3 striver, Dec 28, 2020
  4. striver

    striver Junior Member

    Joined:
    Sep 27, 2020
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    Location:
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    Vehicle:
    2014 Aqua
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    N/A
    replaced booster and accumulator, performed complete bleeding, linear valve and stroke

    works excellent
     
    #4 striver, Jan 1, 2021
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