AIR CONDITIONER - DESCRIPTION

Manual Air Conditioning

DESCRIPTION

The manually operated air conditioning system integrates the heater with the function of producing cold and dehumidified air achieved by switching on the compressor and the cooling system.

The climate control system is controlled by means of three control knobs in the dashboard:

- the left knob controls the hot and cold air mixing flap by means of an electric motor;

- the right knob regulates air ventilation at four different speeds by means of an electrical control;

- the centre knob controls the opening of the flaps that regulate the distribution of air flows by means of an electric motor;

There are 4 buttons under the knobs:

- the first controls the engagement of the air conditioning compressor

See E6021 COMPRESSOR ENGAGEMENT - DESCRIPTION

- the second switches on the recirculation function

- the third activates the MAX-DEF rapid defrosting function (which consists of a collection of measures which make it possible to demist both the windscreen and the rearscreen quickly);

- the fourth button switches on the defrosting of the heating rear windscreen and the door mirrors

See E3030 HEATED REAR WINDSCREEN AND DOOR MIRROR DEFROSTING

The climate control system control unit receives a power supply from a specific direct line protected by a fuse in the junction unit under the dashboard and the fan is protected by a specific fuse in the engine compartment junction unit.

Automatic Air Conditioning

DESCRIPTION

An automatic system manages the passenger compartment climate control, in other words the temperature and the ventilation, with recirculation and direction of the air flows, with separate management for the left and right sides of the passenger compartment.

A special control unit manages the operation of the system by controlling:

- air temperature at the vents - driver''s/passenger side/rear;

- air distribution to the vents;

- fan speed (continuous variation);

- compressor engagement (air refrigeration circuit);

- air recirculation engagement;

- the MAX-DEF rapid defrosting function (which consists of a collection of measures which make it possible to demist both the windscreen and the rearscreen quickly);

The control unit sets the above parameters so that temperature of the passenger compartment is adjusted to the desired temperature. The system controls are located on the outside of the container which houses the control unit.

The following parameters/functions can be altered manually:

- fan speed;

- distribution arrangement;

- compressor disabling;

- defrosting/demisting;

- recirculation.

Manual selections always take priority over automatic ones and are memorized until the user cancels the command by returning to automatic operation.

The control unit acquires information on the temperature and climate conditions both inside and outside the vehicle by means of special sensors:

- outside temperature sensor, located on the driver''s door mirror: the sensor value is acquired by the door node and is then sent, via the CAN, to the climate control system control unit as well as to the instrument panel and to other consumers;

- solar sensor, which measures the sun rays on the windscreen;

- exhaust gas presence sensor (A.Q.S.: Air Quality Sensor): it is located near the windscreen wiper motor and provides a signal when the air pollution index exceeds the pre-set levels: this signal engages the recirculation in order to prevent polluted air from entering the passenger compartment;

- mist sensor: this detects the present of droplets of water (mist) on the inner surface of the windscreen; this information engages the demisting strategy and the air distribution and ventilation are modified. The sensor is built into the electrochromic rear view mirror next to the rain and dusk sensor;

- treated air sensor: a single sensor measures the temperature at the evaporator outlet and transmits this information to the control unit;

- passenger compartment air sensor: this is incorporated in the control unit; it is also suitably ventilated and measures the temperature inside the vehicle.

On the basis of the calculations made, the following are set:

- the speed of the air introduced in the passenger compartment by means of an electronic governor that controls the fan;

- the temperature of the actual air by means of three mixture actuators (one for the right side of the passenger compartment, one for the left side and one for the rear)

- the distribution of the flows with another three actuators (left, right and rear);

- the interior/exterior air recirculation function by means of another specific actuator.

All the actuators are operated by the electronic control unit by means of a BUS communication line.

If the conditions require, the control unit also switches on the air cooling and dehumidification circuit, activating the air conditioning compressor

See E6021 COMPRESSOR ENGAGEMENT - DESCRIPTION

When the outside temperature measured is less than 3 °C the message "Danger, Ice" is shown on the instrument panel display with the snow symbol; this situation is also signalled by a buzzer.

The Body Computer continuously acquires the battery voltage signal to compare it with a limit figure: if the battery voltage measured is below the level, it intervenes via the CAN sending a signal to disable a series of loads: including deactivating the fan operation.

The climate control system control unit receives a power supply from a specific direct line protected by a fuse in the junction unit under the dashboard; the AQS sensor and the mist sensor receive power supplies from the ignition-controlled lines protected by other fuses all in the junction unit under the dashboard; there is a special fuse for the fan in the engine compartment junction unit.