2010 Buick Lucerne Owner's Manual - Page 186

Sensors 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 temperature reading to display. In order to prevent false temperature readings at startup, the displayed temperature will not change until the following occurs: . Vehicle speed is above 10 mph (16 km/h) for five minutes. Vehicle speed is above 32 mph (51 km/h) for two and a half minutes. . 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. There is also an interior temperature sensor located next to the steering wheel that measures the temperature of the air inside the vehicle. The climate control system uses the information from these sensors to maintain your comfort setting by adjusting the outlet temperature, fan speed, and the air delivery mode. The system may also supply cooler air to the side of the vehicle facing the sun. The recirculation mode will also be used as needed to maintain cool outlet temperatures. 4-26