ABS accumulator vs modulator

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by KevinMiller, Jul 21, 2025 at 3:36 AM.

  1. KevinMiller

    KevinMiller New Member

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    Vehicle:
    2007 Prius
    Model:
    LE
    2007 Prius, 107,000 miles

    I am not car-mechanical savvy, as you will see…

    I got all the dashboard brake lights a week ago: BRAKE, (!), ABS, VSC . Still able to drive, but doing so carefully, no freeways.

    -Brake fluid is just below max.
    -12V battery reads 11.3V when not turned on, 14.1V after starting the car.
    -It has been making noise for quite a while; two mechanics told me it was the accumulator making that noise, but didn’t say it was something to worry about. But now here I am…
    -Mileage is lower; tire pressure is fine, so I don’t know if that’s related

    Got an Autozone OBD readout: codes C1256, C1391, C2318 (secondary DTC)

    Mechanic #1 quoted me $3000 (in Los Angeles) without even looking at my car.

    Mechanic #2, did a diagnostic, cleaned voltage connector, found “faulty ABS unit”, quoted me $2600, but for a modulator valve and labor, not a brake accumulator, which is what the OBD codes indicate.

    Wondering if this makes sense. Taking it to be fixed today.

    Thanks for your thoughts.
    20250711_235937.jpg 20250713_195136.jpg 20250713_195150.jpg
     
    #1 KevinMiller, Jul 21, 2025 at 3:36 AM
  2. Tombukt2

    Tombukt2 Senior Member

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    Whatever you're calling it you're buying the same part . It's all in one unit.
     
    #2 Tombukt2, Jul 21, 2025 at 1:36 PM
  3. JC91006

    JC91006 Senior Member

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    Buy the part and I’ll have someone install it for $500. New part is the way to go with your low mileage car
     
    #3 JC91006, Jul 21, 2025 at 1:50 PM
  4. rjparker

    rjparker Tu Humilde Sirviente

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    #4 rjparker, Jul 21, 2025 at 1:51 PM
  5. ChapmanF

    ChapmanF Senior Member

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    Different Prius generations have divvied up the brake components differently. As long as your car is a gen 2 (2004–2009), your accumulator is part of the actuator (or 'modulator') assembly, so you don't need to worry about it. In some other generations, they're in separate assemblies.
     
    #5 ChapmanF, Jul 21, 2025 at 2:10 PM
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