2399363 - E6020 AIR CONDITIONING - Description (Two-zone climate control system)

Description

An automatic system manages the passenger compartment climate control, i.e. temperature and ventilation with recirculation and air flow orientation, with separate management of the temperature for the left and right hand sides of the passenger compartment.

A dedicated control unit manages system operation by controlling:

• air temperature at the driver/passenger vent;
• Air distribution to the vents.
• speed of the fan (varies continuously);
• activation of the compressor (air refrigeration circuit);
• activation of air recirculation;
• The MAX-DEF fast defrost function (i.e. a set of actions which allow both the windscreen and the rearscreen to be demisted quickly);

The control unit sets the above parameters in order to adjust passenger compartment temperature to the required level. The system controls are located outside the control unit housing.

The following parameters/functions can be modified manually:

• fan speed;
• distribution direction
• compressor disablement
• defrosting/demisting:
• recirculation.

Manual selections always take precedence over automatic selections and are stored until the user deliberately cancels the command, allowing the automatic device to take control over the relevant function.

The control unit downloads information on interior and exterior temperature and climatic conditions via special sensors.

• exterior temperature sensor, locate on the driver's side door mirror. The sensor reading is downloaded by a control unit on the door and filtered as necessary; it is then sent via the CAN network to the climate control system ECU (to instrument panel and other appliances).
• lower mixed air temperature sensor (right and left);
• upper mixed air sensors (right and left);
• sunlight sensor, which measures the sun's rays on the windscreen;

After processing the information, it adjusts passenger compartment air intake speed by means of the fan motor and air temperature by means of two mixer actuators (one for the right side and one for the left). It also controls flow distribution via another actuator and - lastly - the interior/exterior air recirculation function via a final actuator. When required, the control unit also controls the engagement of the air cooling and dehumidifying circuit, activating the air conditioning compressor.  See E6021  COMPRESSOR ENGAGEMENT For more details,  Characteristic of working principle 5040  AIR CONDITIONING CASING AND COMPONENTS . The vehicle speed signal - received by the CAN network - is used to filter outdoor temperature and adjust ventilation and the dynamic air intake according to car speed.When the outside temperature measured is less than or equal to 3 °C, the instrument panel display shows the 'Ice Danger' message with the (snow) symbol; this situation is also signalled through the buzzer.The climate control system control unit is supplied by two lines, one direct and one controlled by the ignition, protected by fuses in the underdashboard control unit. the fan is supplied by a line protected by a special fuse and by a specific relay in the engine compartment control unit.