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"Inverter generator" grinding noise when braking above 7mph?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by CamDiggy, Oct 18, 2012.

  1. CamDiggy

    CamDiggy Junior Member

    Joined:
    Aug 31, 2012
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    Location:
    Austin, TX
    Vehicle:
    2007 Prius
    Model:
    N/A
    So after my crazy dealership shenanigans... (POST HERE)

    My car was making a weird grinding noise when braking above 7mph. I did the neutral brake thing and seems to go away sometimes. The dealership said it needed new rotors and brakes, so I went ahead and did that with them, then called me to let me know the sound did not go away. Now they are stating my grinding noise is coming from the "inverter generator" which is what they said was the transmission. I am just curious why this goes away sometimes and if it's related to my previous issues with the car.

    Any input would be great again!
     
  2. jdcollins5

    jdcollins5 Senior Member

    Joined:
    Aug 30, 2009
    5,131
    1,338
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    Location:
    Wilmington, NC
    Vehicle:
    2010 Prius
    Model:
    III
    Above 7 mph your braking is accomplished with Motor/Generator 2 (MG2) reversing current direction and recharging the HV battery. This is called regen braking and what the dealer is describing as the Inverter Generator. MG2 resides in the Prius transaxle as the Prius does not have a transmission like most cars.

    When you go below about 7 mph the car switches to friction braking (brake pads) so any MG2 noise would go away. Also when you switch to neutral you disable the HV battery which disables regen braking and forces friction braking. Once again the MG2 noise would go away.

    This does sound like a problem with your transaxle which can be a four figure repair cost.