Any safe electrical precaution before operating on a Prius?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by priusplus_fr, Jul 23, 2018.

  1. priusplus_fr

    priusplus_fr New Member

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    Hi everybody!
    I have read that i change the brake pads / rotors on the Prius, I have to disconnect the battery.

    I would like to know if in other maintenance operations, you have also to disconnect the battery
    and if there are others cases /specific parts of the car where I have to be careful to prevent any electrical injuries.

    Thanks for your feedback.
     
  2. Bay Stater

    Bay Stater Senior Member

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    It is not necessary to disconnect the battery for all non electrical work. I have done the plugs and the whole EGR and engine component cleaning without disconnecting the battery.
     
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  3. ChapmanF

    ChapmanF Senior Member

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    The recommendation about unhooking the 12 volt battery for brake work isn't anything about electrical safety, it's just to make sure the car doesn't schedule any of its brake self-tests for a moment when you've got your fingers in there. (Even when your fingers are safe, a self test with a caliper removed from the rotor can eject the piston and make a wet mess that is more work to clean up).

    The whole electrical-safety fear with the Prius is a little overplayed. Everything in the high-voltage system is colored orange. As long as you will be doing work that does not involve orange things, and the car has not posted any Diagnostic Trouble Code that indicates a voltage leak, it is like any other car to repair.

    -Chap
     
  4. Mendel Leisk

    Mendel Leisk Titanic Social Director

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    ^ This.

    Notice that noise when you open the driver's door first thing in the morning? That noise can ruin your day if it happens when the caliper's off the rotor: it can push the piston out of the caliper bore.

    Also, when you've reassembled the brakes, before reconnecting the 12 volt (just the negative post cable is sufficient, to disconnect/reconnect): pump the brake pedal several times, to ensure any excess free play is taken up. The car can detect excess brake pedal travel, throw a code.

    Is your 2012 Prius+ MPV comparable to the US/CDN Prius v? The latter has a small drum brake within the rear brake rotor, for parking brake function?
     
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