Depending upon engine model, two different air conditioning compressors are used:
The Electronic Automatic Temperature Control (EATC) controls the passenger compartment temperature automatically for two zones according to the settings made by the driver/front passenger.
The pushbuttons are located in the floor console instrument panel beneath the multimedia system, or they are integrated in the touch-screen of the navigation device where applicable.
The temperature is regulated by changing the positions of the distribution flaps of the heating and ventilation system.
Automatic mode is exited by switching off the system.
Automatic mode is partially exited when one of the following buttons is pressed, in which case any functions which have not been selected continue to operate automatically:
- Air distribution
- Blower setting
- Recirculated air mode
- Defrost
Automatic control is reactivated by pressing the "Auto" button or by pressing the corresponding button again. The automatic mode is not exited when the temperature is adjusted or the Air Conditioning (A/C) button is pressed.
Blower controller: Automatic mode
Based on driver preference, the blower setting is determined as a function of the following input variables in automatic mode:
- Passenger compartment temperature
- Ambient temperature
- Sun load
- Coolant temperature
- Vehicle speed
Blower controller: Manual operation
The first time a blower control button is pressed, the blower symbol is switched on and the automatic symbol switched off. Each time a blower control button is pressed subsequently, the blower speed is set one step higher or lower. Continuous pressing of a button adjusts the blower speed by one step every 0.4 seconds.
Continuous pressing of the button to adjust the blower speed downwards does not switch off the blower. The OFF button needs to be pressed to do this.
Seven blower speed settings can be adjusted manually. In the "Defrost" setting the blower operates at 80% of the maximum speed, unless the maximum value was selected beforehand.
Air distribution: Automatic mode
In automatic mode the air distribution setting is determined on the basis of the driver requests as a function of the following input variables:
- Passenger compartment temperature
- Ambient temperature
- Sun load
- Air conditioning status
- Coolant temperature
- Vehicle speed
Cold air comes out of the instrument panel air vents during air conditioning operation. During warm-up phase warm air is directed into the footwell.
When the vehicle and the engine are cold, air is directed onto the windshield to prevent cold air from entering the footwell.
The air only comes out of the footwell and defroster vents once the preselected temperature has been reached.
When the air conditioning system is switched off (no A/C symbol) the air flow is directed into the footwell to prevent the windows from misting up.
In order to achieve maximum cooling of the interior air in the case of high passenger compartment and ambient temperatures, the system switches to recirculated air in automatic mode. After reaching the temperature set, the system automatically switches back to fresh air intake. The recirculated air warning indicator does not illuminate when automatic recirculated air control is activated.
Air distribution: Manual operation
Each manual operation causes the automatic display to extinguish and activates the LED of the relevant button, and the previously selected settings are stored.
The air distribution modes (windshield, instrument panel and footwell) can be selected individually or together, i.e. one/two/three mode(s) can be selected or deselected by pressing the corresponding buttons.
Operating one of the previously selected buttons switches off the relevant mode. If all modes are deactivated, the system reverts automatically to automatic mode and adopts the previously selected settings.
Defrost
"Defrost" mode is terminated and all the previously stored modes are activated when one of the following settings is selected:
- The "Auto" button is pressed.
- Temperature controllers are actuated.
- The "Defrost" button is pressed again (if it was previously set to "OFF" then the system switches over to "Auto").
- One of the air distribution buttons is pressed.
ECO mode
The EATC transmits the A/C request signal to the GEM via the CAN bus. The signal is then relayed by the GEM via the instrument cluster to the PCM, which actuates the A/C compressor clutch and the cooler fan motor. The EATC request can be interrupted by the PCM, e.g. during full load operation.
In the "Auto A/C" mode, the air conditioning is activated when the user's temperature selection makes this necessary.
Pressing the "A/C" button in "Auto A/C" mode switches the system to the "ECO" status and the compressor is switched off.
Recirculated air mode
Selection of the "Auto" mode results in automatic recirculated air control without the recirculated air LED being switched on.
Pressing the "Recirculated air" button while the LED is switched off selects recirculated air mode; pressing the button again cancels the recirculated air mode and returns the air inlet blend door to the fresh air position.
Recirculated air mode is activated automatically by switching the system off (pressing the "OFF" button). After the system has been activated (i.e. any button has been pressed), the previous settings are called back up.
Temperature adjustment
In "dual mode" the driver and front passenger temperature settings are combined together. As a result, any adjustment of the control elements on the driver's side will adjust the temperature on both sides of the vehicle.
The temperature can be individually adjusted by pressing the driver's side control elements.
Press the "Auto" button for longer than two seconds to switch back and forth between dual temperature controls and individual temperature controls. The display then switches from "Auto" to "Mono".
The temperature can be adjusted in steps of 0.5 °C between 16 °C and 28 °C. Temperature values outside this range are indicated on the display with either "LO" or "HI".
The maximum difference between the temperature on the driver's and front passenger's sides is 4 °C in "Auto" mode. If a greater difference is selected then the opposite side automatically tracks the new temperature setting with a difference of 4 °C.
When "HI" or "LO" are selected the same temperature settings are set on both sides. On both sides of the vehicle the temperature is set to 28°C when any button is pressed after the "HI" mode is switched off, and similarly the temperature is set to 16 °C on both sides when any button is pressed after the "LO" mode is switched off.
In the "HI" setting the system limits the maximum temperature to 28 °C.
Each press of the button increases or decreases the temperature by one step. Continuous pressing of the button changes the temperature setting every 0.4 seconds.
In vehicles with "Bluetooth & Voice Control" function (activation via the "Voice" button on the steering column stalk) the temperature and blower speed can be modified via the voice function.
External controller - EATC
