I have been a car guy for maybe 50 years, repaired many different models, even had my own shop for a while. My 2009 just developed a strange problem. There is a whining noise from under the coolant expansion tank even when the key is off. An electrical fault perhaps? Only shuts off when I pull off the battery cable. Strange. Maybe a relay malfunction? Guess I will pull out the expansion tank and see what component is located underneath it. Can't seem to find it in my Haynes manual. Car has 150k miles.