When it is really cold latley, I have a noise like a little fan spinning at high rpm. Starts when I turn on the ignition, even before the car starts and goes away about 3 minute later. I took off the cover for the ECU and it sounded like it was right in there. Dealer couldn't hear it as it wasn't doing it when I stopped in. They though it might be a fan in the ECU but I don't think that there is one in the ECU. It's no big deal but I just wondered if anyone else has or had it. The regular heating fan still works fine so it isn't envoled.