Usually happen first thing in the morning when I start the car but sometime when I am on the road. I heard high pitch frequency noise, seem like it is coming from the dashboard... The noise somthime last from 10 second to 2 mins. I have taken it a few time to the dealer and they can't diagnost the problem...but the sound just doesn't go away... I think there is a probelm since I read other forum and people is having the same problem.