312001116 - E6020 AIR CONDITIONER - DESCRIPTION (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.