2006 GMC Sierra 1500 Pickup Owner's Manual - Page 205

9(Off): Press this button to turn off the entire climate control system. Outside air will still enter the vehicle, and will be directed to the floor. This direction can be changed by pressing the mode button. The temperature can also be adjusted using either temperature knob. Press the up or down arrows on the fan switch, the defrost button, the AUTO button, or the air conditioning button to turn the system on when it is off. Manual Operation You may manually adjust the air delivery mode or fan speed. The switch with the fan symbol allows you to manually adjust the fan speed. Press the up arrow to increase fan speed and the down arrow to decrease fan speed. Pressing this button when the system is off will turn the system on. H (Panel): This setting will deliver air to the instrument panel outlets. )(Bi-Level): 6 (Floor): outlets. This setting will deliver warmer air to the floor and cooler air to the instrument panel outlets. This setting will deliver air to the floor - (Defog): See "Defogging and Defrosting" later in this section. @(Recirculation): Press this button to limit the amount of outside air entering your vehicle. The light on the recirculation button will glow. This is helpful when you are trying to limit odors entering your vehicle and for maximum air conditioning performance in hot weather. Press this button again to allow outside air to enter the vehicle. The light on the recirculation button will go off. Pressing this button also cancels the auto recirculation feature. To resume the auto recirculation function, press the AUTO button. Each time the vehicle is started, the system will revert to the auto recirculation function. If you select recirculation while in defrost, defog or floor, the light in the button will flash and then go out to let you know that this is not allowed. This is normal and helps to prevent fogging. w9x (Fan): C (Mode): Press this button to manually change the direction of the airflow in your vehicle; repeatedly press the button until the desired mode appears on the display. If you press the mode button to select an air delivery mode, the display will change to show you the selected air mode delivery. The display will then show the current status of the system. When the system is turned off, the display will go blank after displaying the current status of the system. 3-27