2002 Cadillac DeVille Owner's Manual - Page 206

Automatic Operation AUTO: This button is used to select the automatic operation of the climate control system. When the automatic operation is active, AUTO will appear on the display. A sensor will control the air delivery mode. Air will come from the floor, the instrument panel or windshield outlets. The fan speed and use of air conditioning will vary as the system maintains the selected temperature setting. Do not cover the electronic solar sensor located on top of the instrument panel near the windshield. The sensor is used by the automatic system to regulate temperature. See "Electronic Solar Sensor" later in this section for more information. To find your comfort zone, start with the 75_F (24_C) setting and allow about 30 minutes for the system to regulate. Turn the driver's temperature knob to adjust the temperature if necessary. If you choose 60_F (16_C), the system will remain at that maximum cooling setting and will not regulate fan speed. If you choose 90_F (32_C), the system will remain at that maximum heating setting and will not regulate fan speed. Choosing either maximum setting will not cause the system to heat or cool any faster. In cold weather, when the system senses the need for heat, the airflow will be directed out of the floor outlets. As the interior temperature approaches the desired setting, the fan speed will decrease. To maintain interior comfort, the airflow may move to the instrument panel air outlets and floor outlets (bi-level mode). On bright sunny days in cold weather, the airflow may come out of the instrument panel outlets in A/C mode to maintain comfort and prevent stuffiness. When the automatic setting is active, the air conditioning compressor cycles when needed to cool the air. If your vehicle is sitting out on a hot day and AUTO is active, the air will first flow out of the floor outlets for a few seconds. This is normal. This is to remove hot air from the air outlets. As the air is cooled, the airflow will move through the instrument panel outlets. If you start your vehicle with the fan setting on HI, it will skip the air conditioning purge and the system will be in manual mode. 3-4