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ECB blink codes 2012 Prius Four - please translate?

Discussion in 'Gen 3 Prius Technical Discussion' started by chaddarack, Aug 1, 2024.

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  1. chaddarack

    chaddarack Junior Member

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    2012 Prius
    Model:
    Four
    If anyone has access to the manuals and can translate the blink codes to actual codes/errors, please help.

    I have no related engine codes or battery codes, these are the electronic braking system codes. They all come on my dash with an incessant beeping, even without engine trouble codes. The electronic controlled braking system doesn't seem to be giving me regenerative braking, because I feel a lack of braking until the mechanical brakes kick in. My guages show regenerative baking but it feels different in the pedal. The mechanical brakes seem to work well. When I jumpered the pins to get my blink codes, I get the following:

    Traction control light: 45
    Tire pressure monitor: 23
    ABS: 42
    ECB ((!)) 52, 53, 56

    I think these are all pointing towards the ECB codes but I can't find them anywhere and haven't gone to download the repair manuals yet. If anybody already has access to the 2012 repair manuals, can you read me those 3 codes?

    Much appreciated!

    PS. This is my "Frankenprius". JDM Gen4 motor in a gen3 prius x 25k miles. I hope to get another 50k miles out of this new motor. No oil consumption and it purrs like a kitten. I hope I didn't mess the harness, but the brake components aren't really near the area where I worked on the motor and I didn't have to disconnect that part of the harness, and these codes only popped up now 25k miles after the motor swap.
     
    #1 chaddarack, Aug 1, 2024
  2. Tombukt2

    Tombukt2 Senior Member

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    Probably just the brake parts going bad on the firewall real common all of that usually not a sensor or anything that beeping is beeping generally because of brake system not holding pressure If you don't see a leak onto the ground from one of the wheels it's internal meaning one of those $800 parts are both of them are going to get replaced seems like it's right on schedule by mileage and engine change and all that doing exactly what it's supposed to do. But I can't tell you the blink codes the scanner that's ABS capable should give you real codes for the ABS I know I know.
     
    #2 Tombukt2, Aug 1, 2024
  3. ChapmanF

    ChapmanF Senior Member

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    Model:
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    52 is the "real" code C1252.

    53 is the "real" code C1253.

    56 is the "real" code C1256.

    (Don't fall too in love with that pattern: it is not true that every xy blink code is C12xy. It just happens all three of these fit that pattern.)

    C1252 means the brake ECU tried to make the pump run for a crazy long time (over a minute and a half in your case) without succeeding in pumping up the pressure. (It would take nearly three minutes to set this code if the ECU were sure the pump is getting power, but it's not sure of that: see the next code.)

    C1253 means a problem with the pump motor relay(s). The ECU has inputs that monitor the relay outputs, so it can confirm the relay closed to give power to the pump. Your ECU is not convinced that's happening.

    Do you hear the pump running at all when expected? That's the sound like a little joy buzzer or rattlesnake.

    C1256 means the pressure is too low—completely unsurprising if the pump isn't running, of course.

    Because of the C1253, I would probably make at least a cursory examination of the electrical paths to power the pump (there are some troubleshooting steps in the repair manual to give ideas for that) before just replacing an expensive part. On the other hand, because I think the pump relays in this generation are built into the brake actuator, even if they are the problem, you could end up making Tom right and replacing the actuator.
     
    #3 ChapmanF, Aug 1, 2024
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