2008 Cadillac STS Owner's Manual - Page 209

The right knob controls the air delivery to the rear passengers. Turning the knob all the way to the left will shut off airflow to the rear passengers. Operating with the rear air delivery off may make the entire vehicle warm or cool less quickly. It may also increase the air rush sound of the front system. two climate control knobs on the rear climate control panel, to control the rear heated seats. See Heated Seats on page 1-7 for additional information. Be sure to keep the area under the front seats clear of any objects so the air in your vehicle can circulate effectively. 9 (Off): This is the off position. Y (Vent): This mode directs all the rear passenger airflow to the outlets in the console. This is the normal position for cool down conditions. Passenger Compartment Air Filter Your vehicle may be equipped with a passenger compartment air filter. There are two types of filters available. There is a standard dust filter that traps small particles including pollen. There is, also, a dust/odor filter available that traps dust and pollen and also uses a charcoal element to help reduce many offensive odors from entering your vehicle. The filter will need to be changed periodically. For information on how often to change the passenger compartment air filter, see Scheduled Maintenance on page 6-4. Notice: Driving without a passenger compartment air filter in place can cause water and small particles, like paper and leaves, to be pulled into your climate control system which may cause damage to it. Make sure you always replace the old filter with a new one. \ (Bi-Level): [ (Floor): This mode directs airflow to the console outlets and the floor. This mode directs all of the airflow to the floor. This is the normal position for warm up conditions. The amount of airflow to the rear passengers is controlled automatically by the front climate control system, regardless of optional equipment. Airflow to the rear system will be turned off when defrost is selected on the front climate control panel to direct air to clear the windshield. Vehicles equipped with a rear climate control panel, also, have heated rear seats. There are two buttons, each with three indicator lights, located between the 3-55