2003 Chevrolet TrailBlazer Owner's Manual - Page 178
2003 Chevrolet TrailBlazer Manual
Page 178 highlights
Automatic Operation Press the AUTO button to set the system to automatically control the air delivery mode, fan speed, air temperature and recirculation operations. Whenever you press AUTO, the display will change to show the current driver's set temperature, automatic air delivery mode and fan speed. Press the AUTO button again within five seconds and the display will show the passenger's set temperature. After five seconds the display will change to the EXT (external) temperature outside the vehicle. When AUTO is selected, the air conditioning operation and air inlet will be automatically controlled. The air conditioning compressor will run when outside temperature is over approximately 40_F (4_C). The air inlet will normally be set to outside air. If it's hot outside, the air inlet will automatically switch to recirculated inside air to help quickly cool down your vehicle. To find your comfort setting, start with a 74_ F (23_C) temperature setting and allow about 20 minutes for the system to regulate. Turn the driver's or passenger's side temperature knob clockwise or counterclockwise to adjust the temperature setting as necessary. If you choose the temperature setting of 60_F (15_C), the system will remain at the maximum cooling setting and fan speed. If you choose the temperature setting of 90_F (32_C), the system will remain at the maximum heat setting and fan speed. Choosing either maximum setting will not cause the system to heat or cool any faster. Be careful not to cover the sensor located on the top of the instrument panel near the windshield. This sensor regulates air temperature based on sun load, and also turns on your headlamps. The EXT (exterior) temperature sensor is located in the front of the vehicle behind the grille. The displayed temperature is most accurate after the vehicle has been moving for a few minutes. If the vehicle is stopped and then restarted within 2 1/2 hours, the sensor will be hot from the engine heat. In this case, the temperature first displayed will continue to be the temperature that was displayed before the vehicle was turned off. The display will update after the vehicle has been moving for a few minutes and the sensor has a chance to cool down to the actual temperature. To avoid blowing cold air in cold weather, the system will delay turning on the fan until warm air is available. The length of delay depends on the engine coolant temperature. Pressing the fan switch will override this delay and change the fan to a selected speed. 3-6