Chevrolet Suburban 2007 Owner's Manual page 230

Sensors
The solar sensor, located in the defrost grille in
the middle of the instrument panel, monitors
the solar radiation. Do not cover the solar sensor
or the system will not work properly.
230
The interior temperature sensors located in the
headliner above the driver side seat and in
the headliner above the second row seats
measure the temperature of the air inside your
vehicle.