The HVAC system maintains the selected vehicle interior temperature by heating and/or cooling the air.
- During A/C operation, the system also reduces the relative humidity of the air.
- The driver may override the automatic mode of operation.
- The temperature control setting determines the desired air temperature.
- The blower motor control override button varies the blower motor speed.
- The driver side and passenger side temperature settings can be individually controlled.
The HVAC system operation is determined by the settings on the climate controls. The HVAC system automatically maintains a selected temperature for vehicle interior comfort. To control the various functions, the HVAC system is composed of the following:
- HVAC module
- Front Controls Interface Module (FCIM)
- Audio Front Control Module (ACM) or Front Display Interface Module (FDIM)
- Blower motor speed control
- Mode door actuator
- Air inlet door actuator
- Driver and passenger temperature blend door actuators
- In-vehicle temperature sensor
- Ambient temperature sensor
- Solar radiation sensor
- Evaporator temperature sensor
When the DATC system is set to AUTO:
- the air distribution direction, blower motor speed and A/C compressor operation are automatically controlled based on the temperature(s) selected.
The DATC system manual override settings:
- allow the air distribution direction to be manually selected.
- allow the blower motor speed to be manually selected.
- allow recirculation mode to be manually selected in all modes except DEFROST. The A/C request can be cancelled by pressing the A/C request switch, turning the indicator OFF.
- allow A/C compressor operation to be manually selected except in DEFROST.
System Airflow Description — Dual Automatic Temperature Control (DATC)
AUTO
When AUTO is selected:
- the temperature control setting is manually set to the desired setting.
- the air inlet door actuator is automatically controlled by the HVAC module, based on the temperature setting.
- the mode door actuators are automatically controlled by the HVAC module, based on the temperature setting.
- the A/C compressor is automatically controlled by the HVAC module, based on the temperature setting. The A/C compressor will not operate if the outside temperature is below approximately 6°C (43°F).
- the A/C request button or the RECIRC request button, if pressed, will transfer the system to semi-auto operation.
- the blower motor is ON. The blower motor speed is automatically controlled by the HVAC module, based on the temperature setting, but can be manually overridden.
OFF
When OFF is selected:
- the RECIRC request button is disabled.
- the air inlet door actuator closes off outside air and admits only recirculated air.
- the floor/defrost/panel door actuator is in the DEFROST position.
- the A/C request button is disabled.
- the blower motor is OFF.
PANEL
When PANEL is selected:
- the RECIRC request button is enabled. If the RECIRC request button is selected (indicator ON), the air inlet door actuator closes off outside air from entering the passenger compartment. If the RECIRC request button is not selected (indicator OFF), the air inlet door actuator admits only outside air into the passenger compartment.
- the floor/defrost/panel door directs airflow to the instrument panel A/C registers.
- blended air temperature is available. Only when A/C compressor operation has been selected by pressing the A/C request button (indicator ON), can the airflow temperature be cooled below the outside air temperature.
- the A/C request button is enabled. The A/C compressor will operate and the indicator will illuminate if the A/C request button is selected and the outside temperature is above approximately 6°C (43°F).
- the blower motor is ON.
PANEL/FLOOR
When PANEL/FLOOR is selected:
- the RECIRC request button is enabled. If the RECIRC request button is selected (indicator ON), the air inlet door actuator closes off outside air from entering the passenger compartment. If the RECIRC request button is not selected (indicator OFF), the air inlet door actuator admits only outside air into the passenger compartment.
- the floor/defrost/panel door directs airflow to the floor duct and the instrument panel A/C registers. A small amount of airflow from the side window demisters and defrost duct will be present.
- blended air temperature is available. Only when A/C compressor operation has been selected by pressing the A/C request button (indicator ON), can the airflow temperature be cooled below the outside air temperature.
- the A/C request button is enabled. The A/C compressor will operate and the indicator will illuminate if the A/C request button is selected and the outside temperature is above approximately 6°C (43°F).
- the blower motor is ON.
FLOOR
When FLOOR is selected:
- the RECIRC request button is enabled. If the RECIRC request button is selected (indicator ON), the air inlet door actuator closes off outside air from entering the passenger compartment. If the RECIRC request button is not selected (indicator OFF), the air inlet door actuator admits only outside air into the passenger compartment.
- the floor/defrost/panel door directs airflow to the floor duct. A small amount of airflow from the defroster duct and side window demisters will be present.
- blended air temperature is available. Only when A/C compressor operation has been selected by pressing the A/C request button (indicator ON), can the airflow temperature be cooled below the outside air temperature.
- the A/C request button is enabled. The A/C compressor will operate and the indicator will illuminate if the A/C request button is selected and the outside temperature is above approximately 6°C (43°F).
- the blower motor is ON.
FLOOR/DEFROST
When the FLOOR/DEFROST is selected:
- the RECIRC request button is enabled. If the RECIRC request button is selected (indicator ON), the air inlet door actuator closes off outside air from entering the passenger compartment. If the RECIRC request button is not selected (indicator OFF), the air inlet door actuator admits only outside air into the passenger compartment.
- the floor/defrost/panel door directs airflow to the floor duct, the defroster duct and the side window demisters.
- blended air temperature is available.
- the A/C request button is enabled. The A/C compressor will operate automatically and the indicator will illuminate if the A/C request button is selected and the outside temperature is above approximately 6°C (43°F).
- the blower motor is ON.
DEFROST
When DEFROST is selected:
- the RECIRC request button and indicator is disabled. Regardless of button and indicator status, the air inlet door actuator admits only outside air into the passenger compartment.
- the floor/defrost/panel door directs airflow to the defroster duct and side window demisters. A small amount of airflow from the floor duct will be present.
- blended air temperature is available.
- the A/C request button will indicate the last status and the indicator can be toggled. To reduce fogging, the A/C compressor will operate automatically, regardless of indicator status, if the outside temperature is above approximately 6°C (43°F).
- the blower motor is ON.
