Hi all,

I've had a 2009 ES350 for the past 5 years. Recently it has started to emit a constant high pitched noise (whine) in the cabin when the temperature drops to around freezing. The weird thing is that this noise happens when the vehicle hasn't been started and also continues when it's started and driving. It just started a couple of weeks ago when we got a cold spell for 2-3 days, then we got a few days above freezing and the sound went away. Today it was a little colder and it's back. I've shut off the radio, removed some usb connections I had to aux etc. and no luck. I've tried to localize where the sound is coming from by moving my head around and trying to locate a source but also no luck.

Anyone else had this issue?

 

Have you tried disconnecting the battery?

 

You mean as a way of resetting it somehow? No, I haven't tried that yet but I will next time it happens. This morning it was making the noise again, temperature right around freezing. After driving it around for about 30 minutes of errands I noticed the noise was gone but that might have been the temp going up or the car getting warm, I'm not sure.