194001681 - E6020 AIR CONDITIONER - DESCRIPTION (AUTOMATIC AIR CONDITIONING)

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);- additional engine heating function (JTD versions).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 control unit (NPG) and is suitably "filtered"; it is then sent via the CAN, to the climate control system control unit;- lower mixed air temperature sensors (left and right);- upper mixed air sensors (left and right);- solar sensor, which measures the sun rays on the windscreen;- pollution control sensor (AQS) which measure the pollutionrate of the outside air, determining the opening/closing of the recirculation flap for the air distribution unit.According to the calculations made, the control unit sets the passenger compartment air intake speed through the fan motor and the temperature by means of two mixture actuators (one for the right side of the passenger compartment and one for the left side); it also sets the distributions of the flows through another actuator and, lastly, another actuator is responsible for the inside/outside air recirculation function.If the conditions require, the control unit also switches on the air cooling and dehumidification circuit, activating the air conditioning compressor    See E6021 COMPRESSOR ENGAGEMENTFor more details,    See descriptions 5040 AIR CONDITIONING CASING AND COMPONENTSThe vehicle speed signal arrives via the CAN and is used by the climate control system control unit to filter the outside temperature and compensate for the ventilation and dynamic air intake depending on the speed of the vehicle.When the outside temperature measured is less than or equal to 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 control unit has three supply lines, on direct battery and two ignition operated, protected by fuses in the junction unit under the dashboard; the fan receives a power supply from a line protected by a specific fuse in the engine compartment junction unit.