Mazda 2011 CX-9 Owner's Manual page 256

qSunlight/Temperature Sensor
The fully automatic air conditioner
function measures inside and outside
temperatures, and the intensity of direct
sunlight. It then sets temperatures inside
the passenger compartment accordingly.
CAUTION
Do not obstruct either sensor,
otherwise the automatic air
conditioner will not operate properly.
Sunlight sensor
Interior temperature sensor
Climate Control System
Interior Comfort
6-3