2001 GMC Yukon Owner's Manual - Page 173

Electronic Climate Control System (If Equipped) When both the fan control and mode knobs are in the AUTO position, the system will then automatically maintain the desired cabin temperature as selected by the temperature knob. Manual control of functions is also available. Temperature Knob The middle knob on the control panel lets you select the desired air temperature in your vehicle. This knob will allow you to adjust the interior air temperature independent of the function knob setting. Move the knob clockwise toward 82 for warmer air. Move the knob counterclockwise toward 66 for cooler air. When the system is set for automatic operation, sensors will control the fan/blower speed. Fan Control The knob on the left side of the electronic climate control panel controls the fan speed. To manually increase airflow, move the knob clockwise. To manually decrease airflow, move it counterclockwise. OFF: If the knob is in OFF, outside air will still enter the vehicle, and will be directed based on the position of the mode knob. AUTO: If the knob is in AUTO, the fan speed will vary as the system maintains the selected temperature. Full Hot: If you turn the temperature knob past 82_F (28_C), the system will go into the "full hot" mode. The system will remain at that maximum heating setting and the fan will blow at the speed the fan knob is set to. If the fan is in AUTO, it will run at full speed. Full Cold: If you turn the temperature knob past 66_F (19_C), the system will go into the "full cold" mode. The system will remain at that maximum cooling setting and the fan will blow at the speed the fan knob is set to. If the fan is in AUTO, it will run at full speed. 3-5