It's the solar gain sensor for the climate control system.
The climate control system uses some form of fuzzy logic to decide the
auto climate control settings.
You'll probably feel warmer with the noonday sun beating down at you,
than if it was overcast outside, even for the same outside
temperature. The same sun that makes you feel warm will also be
trying to warm up the interior (so in the summer with the AC on the AC
would have to be on cooler or a faster fan speed than if it wasn't
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.