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prius v 2012 antiskid ecu

Discussion in 'Prius v Main Forum' started by Marcel Nault, Jun 9, 2024.

  1. Marcel Nault

    Marcel Nault Junior Member

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    In the service manual, they mention the ecu skid control ecu. Does any know whete it is located?
     
  2. rjparker

    rjparker Tu Humilde Sirviente

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    It is part of the brake booster. Which is why brake booster are expensive.
     
  3. Marcel Nault

    Marcel Nault Junior Member

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    Having an issue with the anti-skid....the stop light is allways on, have to disconect the battery . As per the service manual, and some voltage test done, it should come from the skid control ecu...But where is located this ECU skid control?...not mentioned in the service manual..not sure but may be near the power brake in the engine compartment...
     
  4. rjparker

    rjparker Tu Humilde Sirviente

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    Check your first thread on the subject
     
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  5. Tideland Prius

    Tideland Prius Moderator of the North
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    Threads merged
     
  6. Marcel Nault

    Marcel Nault Junior Member

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    Thanks, but can the ecu be take out from the assembly brake booster
     
  7. rjparker

    rjparker Tu Humilde Sirviente

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    No. The built in skid ecu is one reason used brake boosters sometimes don’t work. The code is different between years, models like hatchback vs a v wagon and even tire size.
     
  8. Marcel Nault

    Marcel Nault Junior Member

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    need to change the complete master booster cylinder with it.

    Just found this on how to remove the ecu:

    Firstly, removed the firewall [can find video instructions on the web], it was simply removing the wiper blades and two lock pins in top plastic part. Then remove wiper motor assembly. Then un screw 12 bolts to remove steel cover.

    Then ECU can be seen parallel to the brake pedal.

    Before dealing with the ECU it’s a good idea to remove the negative terminal of battery. [or you can keep the drivers door open during the process and keep the key far away from the car so there is no brake pressuring during the time. Yes, car has to be off during the time.

    Remove two bolts in the brake fluid reservoir bracket and clear the way to ECU.

    Remove the communication cable connected to the ECU.

    Remove two hoses from brake reservoir to ECU. It’s a good idea to block the hose, while its disconnected. And the un screw the brake 4 distribution steel pipes using 10’ key and the pressure line [red pipe].

    Now dip below the steering wheel and remove the below plastic cover. And unscrew the 4 bolts around brake pedal. These bolts attaches the ECU to the chassis. This is the most time consuming and toughest work out of all, required lot of patience.

    Remove the brake light switch and then remove the pin and the, which goes across the brake pedal lever. Now we can take the ECU out.

    Now go in the reverse order to fix the new ECU.
    Now dip below the steering wheel and remove the below plastic cover. And unscrew
    the 4 bolts around brake pedal. These bolts attaches the ECU to the chassis.
    This is the most time consuming and toughest work out of all, required lot of
    patience.
    Remove the brake light switch and then remove the pin and the, which goes across
    the brake pedal lever. Now we can take the ECU out.
    Now go in the reverse order to fix the new ECU.
    I faced the difficulty since it was a LHD ECU and the car is RHD. It was the
    drivers side front wheel brake pipes giving problem to fix. But go ahead and
    bend the pipe if you face the same situation.
    Prior connecting the Communication cable, make sure your reservoir has fluid at
    least to mid level. This level will come down soon, since ECU has to be filled
    with fluid.
    After everything is fixed. And making sure hoses and pipes are properly
    tightened. Switch on the car [not ready mode] check for any DTCs. Clear them if
    theres any. You’ll have to calibrate the linear solenoid valve. Before resetting
    as in instructions make sure you run the test mode [unless this can cause a huge
    problem, you might have to look for another ECU].
    If its other side ECU [as I experienced] DTCs will say “wrong ECU connected” don’t worry. Switch off the car and restart the calibration. You might have to
    do this few times. But it should work.
    Check the fluid level during the process and refill if it goes below mid level.
    Finally release air from brake lines.
    Take the car for a test ride. Do some panic brakes straight and while turning to
    each side. And get comfortable with braking.
    Monitor the MGP gains and rotor heating for some time, just to ensure its
    working perfect.
     
  9. rjparker

    rjparker Tu Humilde Sirviente

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    That very old post from an overseas guy has a lot lost in translation. You certainly don’t remove the firewall and his use of “ecu” term for the brake booster (a combination of the master cylinder/abs/skid ecu) was confusing at best and inaccurate at worst.

    He does not mention the separate brake booster pump which builds hydraulic pressure.

    You also need Techstream for flushing the many paths inside the booster and for calibration.

    Brake Booster and Pump
    IMG_5378.jpeg