3234645 - E6020 AIR CONDITIONING - Description (Two-zone climate control system)

Description

An automatic system manages the passenger compartment climate control, i.e. temperature and ventilation with recirculation and air flow orientation, with separate management of the temperature for the left and right hand sides of the passenger compartment (bi-zone system).

A dedicated control unit manages system operation by controlling:

  • air temperature at the driver/passenger vent;
  • air distribution to the vents;
  • speed of the fan (varies continuously);
  • activation of the compressor (air refrigeration circuit);
  • activation of air recirculation;
  • The MAX-DEF fast defrost function (i.e. a set of actions which allow both the windscreen and the rearscreen to be demisted quickly);
The control unit sets the above parameters in order to adjust passenger compartment temperature to the required level. The system controls are located outside the control unit housing.

The following parameters/functions can be modified manually:

  • fan speed
  • distribution direction
  • compressor disablement
  • defrosting/demisting:
  • recirculation
Manual selections always take precedence over automatic selections and are stored until the user deliberately cancels the command, allowing the automatic device to take control over the relevant function.

The control unit downloads information on interior and exterior temperature and climatic conditions via special sensors.

  • outdoor temperature sensor located on the driver side door mirror.
  • lower mixed air temperature sensor (right and left);
  • upper mixed air sensors (right and left);
  • passenger compartment temperature sensor
  • sunlight sensor, which measures the sun's rays on the windscreen;
  • exhaust gas presence sensor (A.Q.S.: Air Quality Sensor):supplies a signal when the air pollution index exceeds a preset level of harmfulness. This signal turns on the recirculation to prevent polluted air entering the passenger compartment;
  • demisting sensor, which detects the presence of water droplets (mist) on the inner surface of the windscreen; this information turns on the relevant demisting strategy., which alters the air and ventilation distribution pattern.
After processing the information, it adjusts passenger compartment air intake speed by means of the fan motor and air temperature by means of two mixer actuators (one for the right side and one for the left). it also sets flow distribution with another actuator and - lastly - interior air/exterior air recirculation via a final actuator. When required, the ECU automatically activates the cooling circuit and dehumidifies the air by operating the air conditioner compressor  See E6021  COMPRESSOR ENGAGEMENT . For more details  Characteristic of working principle 5040  AIR CONDITIONING CASING AND COMPONENTS . The control unit supply lines are protected by a fuse in the junction unit and by the fuse which protects other supplies controlled by the ignition.The fan supply lines are protected by a special maxifuse.The system will only operate when the ignition is turned ON.