I haven't heard this sound correlating to brakes. The car makes the buzzing sound I hear even before it's turned on or after it is turned off. I guess I'll have to get my wife to help and do like you suggested to see if the noise is happening at the same time as the shutters move.
What did you see, GrySql, that you don't think it's the shutters?
The parking brake does make an interesting noise, especially if you are standing alongside the car near a rear wheel, then it's really loud.
The only buzzing I hear from the front of the car that is consistent is when applying the foot brake, in the ready or started mode.
The other buzzing that I thought was the shutters happened while I watched the shutters open, then close - but not every time.
Perhaps the brake booster was buzzing simultaneously.
Tonight there were no sounds when it was started, until I pushed the brake pedal, although the shutters had opened and closed.
Just now, with the car running in EV in the garage, I had my wife push the brake pedal and release it, every time there was a buzzing.
I tried to isolate it's location in the engine bay and it seems to be on the on the back side of the ICE, near the Traction motor, down low.
One would have to remove the large upper plastic engine cover to see back there and I wasn't in the mood.
I could feel the buzz vibration on different parts of the ICE.
The emergency brake has another type of electrical buzzing coming from the rear, which makes sense.
It sure stops well, no complains there.
Edited by GrySql, 06 April 2013 - 11:47 PM.