2008 GMC Sierra 1500 Pickup Owner's Manual - Page 162

Dual Automatic Climate Control System The heating, cooling, and ventilation in the vehicle can be controlled with this system. The vehicle also has a flow-through ventilation system described later in this section. Driver and Passenger Side Temperature Controls The driver and passenger side temperature buttons are used to adjust the temperature of the air coming through the system on the driver or passenger's side of the vehicle. The temperature can be adjusted even if the system is turned off. This is possible since outside air always flows through the system as the vehicle is moving forward unless it is set to recirculation mode. See "Recirculation" later in this section. Press the + or − buttons to increase or decrease the cabin temperature. The driver side or passenger side temperature display shows the temperature setting decreasing or increasing. The passenger's temperature setting can be set to match the driver's temperature setting by pressing the PASS button and turning off the PASS indicator. When the passenger's temperature setting is set different than the driver's setting, the indicator on the PASS button illuminates and both the driver's side and passenger's side temperature displays are shown. Different climate control settings can be selected for the driver and passengers. 3-26