Whine coming from under the hood

[DWG]

Hi, I just picked up a 40th anniversary and was messing around with the bluetooth in the garage and noticed that sometimes when the ignition is in the "ON" position there is a very high-pitched whine/buzzing coming from under the engine cover. It isn't there when the ignition is in the "ACC" position. I can also always hear it for a few seconds after I turn the engine off.

Is this normal for these cars?

It has the Stillen Gen III intake, if that makes a difference.

Thanks,
David

[Bryan]

My nismo makes a small whine also I think its the ecu. I've heard other people here say the same its not loud though and stays for a few seconds after I shut it off sounds like what's happening to you

[DWG]

Originally Posted by Bryan

My nismo makes a small whine also I think its the ecu. I've heard other people here say the same its not loud though and stays for a few seconds after I shut it off sounds like what's happening to you

I'm pretty sure it's coming from under the engine cover, not the dash. I did a little more searching and found this: Whining Noise From Engine Bay

Someone states it is the throttle body. Any more info would be appreciated!

[DIGItonium]

IIRC, it's the throttle body. You can hear it when you put IGN to ON position. When you put it back to OFF, you can hear the TB moving around.