2010 Cadillac STS Owner's Manual - Page 228

The climate control system uses the information from these sensors to adjust the temperature, the fan speed and the air delivery, in order to maintain the selected temperature. The system may also supply cooler air to the side of the vehicle facing the sun. Do not cover the sensors or the automatic climate control system will not work properly. Operation Tips . Clear away any ice, snow or leaves from the air inlets at the base of the windshield that may block the flow of air into your vehicle. Use of non-GM approved hood deflectors may adversely affect the performance of the system. Keep the path under the front seats clear of objects to help circulate the air inside of your vehicle more effectively. If the airflow seems low when the fan speed is at the highest setting, the passenger compartment air filter may need to be replaced. For more information, see Passenger Compartment Air Filter on page 4‑50. . . Outlet Adjustment Use the lever located in the center of each outlet to change the direction of the airflow, either side-to-side or up and down. Use the thumbwheels to open or close the outlets to adjust the airflow. Turn the thumbwheel towards the vehicle door to open the outlets and allow the maximum amount of air to enter your vehicle. Turn the thumbwheel towards the center console to close the outlets and minimize the amount of air entering the vehicle. . 4-48