AIR CONDITIONER - DESCRIPTION

1.2 8v, 1.3 Multijet, 1.4 16v · 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 vehicle climate control system is operated using the four control knobs:

• the left-hand knob mechanically controls the hot and cold air mixing (22 positions);
• the left middle knob allows the regulation, through an electrical control, of the air ventilation at four different speeds (4 positions) and the engagement of the compressor by pressing the ring nut;
• the right middle knob makes it possible to select whether or not to set the "recirculation" function which prevents the intake of new air into the passenger compartment.
• the right knob mechanically controls the opening of the flaps that regulate the distribution of air flows (5 positions).

The transmission of the air mixing, air distribution and recirculation commands from the knobs to the climate control casing takes place by means of bowden cables.

With the compressor enabled, the on switch does not allow the user to zero the fan speed (turn the knob to zero) to prevent the evaporator from freezing.

An LED in the knob allows the compressor status (activated/deactivated) to be signalled.

The electronic thermostat is designed to detect the formation of ice on the evaporator allowing the compressor to be disabled to prevent the evaporator from freezing.

For further details,

See descriptions 5040 AIR CONDITIONING CASING AND COMPONENTS

The fan is controlled by a dedicated relay and is protected by a dedicated fuse located in the engine compartment junction unit.

1.2 8v, 1.3 Multijet, 1.4 16v · Automatic climate control

DESCRIPTION

An automatic system manages passenger compartment climate control, i.e. temperature and ventilation, with air flow recirculation and positioning.

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

• air temperature at the vents;
• air distribution at the vents;
• fan speed;
• 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 the windscreen quickly);

The control unit sets the above parameters so that temperature of the passenger compartment is adjusted to the desired temperature.

The following parameters/functions can be altered manually:

• temperature;
• 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 weather conditions via 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;
• frost sensor: measures the temperature at the evaporator;
• two treated air temperature sensors: measure the temperature at the driver''s lower vent outlet (FOOT) and the upper vent in the centre of the dashboard (VENT) and transmit this information to the control unit;
• passenger compartment air sensor, integrated in the control unit.

On the basis of the calculations made, the control unit sets:

• the speed of the air entering the passenger compartment;
• the temperture of the air through the mixture actuator (MIX);
• the distribution of the flows via a dedicated actuator (DIST);
• the interior/exterior air recirculation function by means of another specific actuator (RIC).

All actuators are controlled directly 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

For further details,

See descriptions 5040 AIR CONDITIONING CASING AND COMPONENTS

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

The climate control system control unit is supplied by two lines, one direct and one ignition-controlled, protected by dedicated fuses located in the Body Computer; the fan is controlled by a dedicated relay and protected by a dedicated fuse located in the engine compartment junction unit.