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Disconnecting ABS System?

Discussion in 'Prius c Main Forum' started by Robert William Aston, Nov 17, 2022.

  1. Robert William Aston

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    Is there any cons to disconnecting the ABS system in a 2015 prius c?
     
  2. John in Vermont

    John in Vermont Junior Member

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    It is illegal to disconnect a safety or pollution control system. The ABS's are complicated enough that I doubt if they can be easily be disconnected, nothing as simple as pulling a single fuse. If you were in an accident you might have increased liability if the ABS was discovered to be bypassed.
     
  3. Elektroingenieur

    Elektroingenieur Senior Member

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    On Prius cars, including Prius c models, ABS is integrated into the electronically controlled brake system; it’s not a discrete set of components that could be disconnected separately. The ABS behaviors are part of the programming of the skid control ECU, which despite its name, is the computer for brake control in general, including power-assisted and regenerative braking. See New Car Features (more info) for more information.
    I’m not sure I’d agree with such a broad statement. It may be unwise, and I’d urge anyone contemplating it to consult with their own attorneys, but as to safety devices, see my previous comments on the “make inoperative” provision of U.S. federal law and the persons to whom it does and does not apply.

    New Zealand law may be different, of course; items 21 and 37 in the Service brake and parking brake section of the VIRM, for example, suggest that a vehicle with installed but inoperative ABS would be rejected in a warrant of fitness inspection.
     
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  4. Kerrynzl

    Kerrynzl Junior Member

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    Brake modifications are legal in NZ but if you re-engineer the braking system you need a "low volume" modification cert.

    I removed the ABS on a BMW E36 that was used as a track car [but still road registered] The ECU had to have it disabled or it would flash the ABS warning light.
    The BMW had stock "M" spec brakes with "Carbon Metallic 90 compound" pads, so I didn't need a mod cert.

    With racing tyres it would brake a shitload better [higher G's] with the ABS disconnected.
    There were probably G force parameters in the original ABS program.

    Personally , I don't have the confidence to remove a Prius C /Aqua ABS
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

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    Why do want to do this?
     
  6. Robert William Aston

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    I have a chronic co-ordination issue and can't be as smooth/gentle applying pressure to brake pedal as i used to be.
     
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  7. Kerrynzl

    Kerrynzl Junior Member

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    Then you absolutely NEED ABS braking . Or you will get front wheel or rear wheel lock-up from "kicking" the brakes.

    But before you Jump In [no pun intended] do a search on "hybrid regenerative braking"

    Quoted from another post on Prius Chat
    With regenerative brakes, on the other hand, the system that drives the vehicle does the majority of the braking. When the driver steps on the brake pedal of an electric or hybrid vehicle, these types of brakes put the vehicle's electric motor into reverse mode, causing it to run backwards, thus slowing the car's wheels. While running backwards, the motor also acts as an electric generator, producing electricity that's then fed into the vehicle's batteries. These types of brakes work better at certain speeds than others. In fact, they're most effective in stop-and-go driving situations. However, hybrids and fully electric cars also have friction brakes, as a kind of back-up system in situations where regenerative braking simply won't supply enough stopping power


    So basically your car's friction pads are not even clamping the discs until absolute maximum emergency, which explains the incredible "life expectancy" of the pads.
    So the ABS would almost be impossible to disable on a Toyota Hybrid.

    The best method for you would require some engineering...... That would be altering the brake pedal pivot ratios.
    or
    You could try adding heavier return springs to the pedal which would require more pedal pressure [And also more pressure for regenerative braking ]

    On conventional brakes I would tinker with the brake booster vacuum / smaller diaphragm booster.


    Have you tried different seat positions? A driving instructor showed me this "secret" when I had a car dealership [The customer always blamed the car, instead of their driving]
     
    #7 Kerrynzl, Nov 20, 2022
    Last edited: Nov 20, 2022
  8. ChapmanF

    ChapmanF Senior Member

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    Do you remember where that other post is?

    The basic point about the regen braking is good, but that post isn't giving a very good explanation of how the regen works.
     
  9. prius16

    prius16 Active Member

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    It was member quoting the BS article from "How stuff works". It was cleared up in posts later the the thread.

    The thread:
    I Finally Understand Hybrid Regenerative Braking | PriusChat

    The original BS InterWeb source:
    How Regenerative Braking Works | HowStuffWorks


    Btw, from the InterWeb, "If you give all of your money and wealth to Prius16, you will live a happy and fulfilling life".
    Really, really! I read it on the InterWeb. :)
    Here's the link: Disconnecting ABS System? | PriusChat
     
  10. Kerrynzl

    Kerrynzl Junior Member

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    I carefully selected excerpts from this.
    I Finally Understand Hybrid Regenerative Braking | PriusChat
    Watch the video below it.

    I wasn't in anyway trying to give a good explanation of how the regen works. But to explain that he shouldn't f*** with the braking because there is another factor involved.
    Regen principles is pretty basic, if the electric motor can accelerate mass, it can also decelerate mass.
    But is the software and integration with different braking systems and power trains that is beyond our level of expertise.

    My advice to @Robert William Aston is to change driving techniques. Maybe learn to anticipate more and react less, or Left foot braking etc etc.
    Try and get out on a track during a track day and get some laps in practicing feel. [or an empty car park]
    [I've seen fathers teaching their kids to drive on the track all the time......It is a safer environment that the street]

    I switched over to left foot braking to allow me to drive deeper into corners .
    When I started doing this [and practicing on the street] it was terrible. Either not enough braking or too aggressive.

    I now brake perfectly with either foot, and sometimes L/F brake and slide my R/F over the pedal to free up my L/F for the clutch pedal.
    I am not suggesting race driving , but developing smooth techniques.

    This is all needed for tyre feedback to the seat of the pants and fingertips holding the wheel.
     
  11. Robert William Aston

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    Actually bud, I wish the pedal hinged on floor rather than being so old-fashioned but tried varying seat positions.no joy ):
     
  12. Kerrynzl

    Kerrynzl Junior Member

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    Whats your foot like on the gas pedal??
     
  13. Robert William Aston

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    beautiful...serious it smooth and controlled
     
  14. mr_guy_mann

    mr_guy_mann Senior Member

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    I don't know the C particulars, but if the braking system is similar to the Gen2, then any significant fault there will cause the hybrid control to disable regenerative braking altogether.

    Safety issues aside, that'll lead to a big reduction in MPGs, more ICE operation and low HV battery SOC, reduced performance when the SOC is too low, etc.

    Posted via the PriusChat mobile app.