Snow yesterday. Cold today. It's only October.

Initially, the climate control gets the cabin temperature to a comfortable temperature.

Then, after driving on the highway for a while it seems to stop warming the car.

I can heat the cabin by turning the heat control waaaaay up, but otherwise it does not seem to accurately adjust the cabin temperature.

The engine temp is as usual, right in the middle of the gauge.

About a year ago, on a veeery cold morning, the ACC lights flashed, once.

No codes in memory, but dealer replaced the cabin temperature sensor. Cabin seemed to be cool inside afterwards, but with spring and summer arriving, this wasn't a problem.

Enough time has elapsed to put about 20,000 miles between the repair and a few miles between the end of the warranty and today.

First, thought I might check the connections to the sensor. If the sensor is not making contact, would it not cause the ACC error lights to flash? Also, I removed the radio, and tried to pop the ACC panel out. Does it actually "pop" out? Are there any blind screws? I think can I feel one to the right of the panel. I don't want to break the dashboard.

I also understand the interior temperature sensor is held in place by a couple of clips. Does it pop out or in?

Also, there reportedly is a tiny fan that draws air into the sensor. Is this a part of the sensor? Or is a separate component? And if the fan fails, will it show an ACC error?

I feel silly driving with my coat on and the seat heaters on when it's 42 degrees outside....

Thanks!