2006 Cadillac DTS Owner's Manual - Page 178

Sensors The solar sensor, located in the defrost grille, middle of the instrument panel, monitors the solar radiation. Do not cover the solar sensor or the system will not work properly. There is also an interior temperature sensor located next to the steering wheel that measures the temperature of the air inside your vehicle. There is also an exterior temperature sensor located behind the front grille. This sensor reads the outside air temperature and helps maintain the temperature inside the vehicle. Any cover on the front of the vehicle could cause a false reading in the displayed temperature. 3-48