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 via mechanical controls;

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

- the right knob controls the opening of the flaps that regulate the distribution of air flows;

There are 3 buttons above the knobs:

- the button on the right engages the recirculation function through an electrically-controlled motor

- the middle button controls the engagement of the air conditioning compressor

See E6021 COMPRESSOR ENGAGEMENT

- the button on the left switches on the demisting of the heating rear windscreen and the door mirrors

See E3030 HEATED REAR WINDSCREEN AND DOOR MIRROR DEFROSTING

The fan receives a power supply from a line protected by a special fuse and operated by a specific relay in the engine compartment junction unit.

The controls receive a power supply from an ignition-controlled line protected by a fuse in the junction unit under the dashboard.

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);

- 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 passenger door mirror: the sensor value is acquired by the Body Computer 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;

- four treated air sensors: measures the temperature at the vent outlet and send this information to the control unit;

- exhaust gas presence sensor (A.Q.S.: Air Quality Sensor): 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; A.Q.S.

- 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 two mixture actuators (one for the right side of the passenger compartment and one for the left side)

- the distribution of the flows with another two actuators;

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

All actuators are controlled by an electronic control unit.

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

When the outside temperature measured is below 3 °C, the message "Danger Ice" and the snowflake symbol flash in the instrument panel display.

There is an additional electric heater available as an option which comes on if the temperature of the engine coolant reaching the heater is extremely low.

See E6015 ADDITIONAL HEATER

The climate control system control unit M70 receives a power supply via two lines, one direct and one ignition-operated, protected by fuses in the junction unit under the dashboard; the fan receives a power supply through a line protected by a specific fuse and a specific relay in the engine compartment junction unit.