Low hum coming from 2011 Highlander while off??

[guyac]

I went into my garage today and there was a low hum coming from the under side of the highlander. It sounded like the hum from a ballast in a fluorescent light. But the car was off, and nothing was on in the car. Went out 5 minutes later and it was gone. Couldn't figure out where or what was causing the noise. Does anyone have any idea what this could be or have heard of this before?

This the 3rd time I've heard it and I don't know how often it's occurring or if I should be concerned.

Thanks,

Andy

[TrailDust]

Hi, Andy!

See the "Humming Motor Sound" link in the Common Problems & Solutions sticky thread. That sound is normal.

[guyac]

Thanks Trail Dust.