841005340 - E6020 AIR CONDITIONING Description

Description

The vehicle climate control system is achieved through the duct/distributor unit and heater. The 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 composed of:

  • controls consisting of knobs and buttons;
  • sensors such as the passenger compartment temperature sensor, outside temperature sensor, left/right dashboard mixed temperature sensor, exhaust gas presence sensor and solar cells;
  • actuators such as the left/right mixture actuators, distribution vents in the dashboard, footwell vents, MAX-DEF function, compressor disabling, fan speed, heated rear windscreen;
  • connection with the CAN to receive signals for the outside temperaure, vehicle speed, engine coolant temperature, state of the compressor and the heated rear windscreen:
  • compressor enabling signal output.
The automatic climate control system manages the temperature, the distribution of the air and the air flow rate inside the passenger compartment on both the driver and passenger sides (front or front and rear) to achieve the desired comfort level.The climate control system control unit manages the following climate control system functions:

  • the selection of the desired temperature and the dashboard air outlets (top, front, footwell and defrost vents);
  • the switching on/off of the compressor, automatic or manual recirculation of the air inside the vehicle;
  • the separation of the two sides (left/right) for the distribution of the air;
  • the engagement of 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 adjustment of the air flow rate, increasing or decreasing it. A number of bars (12 in all) appear on the display showing the level;
  • the switching on of the heated rear windscreen;
  • the transfer of the right side commands to the rear (if present as an option).
The following parameters/functions are regulated automatically:

  • driver's/passenger side air vents temperature (front/rear);
  • driver's/passenger side air vents distribution (front/rear);
  • fan speed;
  • engagement of compressor;
  • recirculation.
Each time it is switched on the system restores the conditions memorized when it was switched off, with the exception of the MAX-DEF function which is zeroed.The control of the temperature is based on the "thermal balance" principle, i.e. the climate control system develops sufficient thermal power to keep the inside temperature set constant and compensate for the thermal energy which the vehicle exchanges with the outside depending on the climate conditions.This automatic climate control system allows the occupants in the front of the vehicle to request the intake of "diffused" air into the passenger compartment. In this configuration the climate control system operates using three additional vents, located in the dashboard, and makes it possible to employ a different internal temperature maintenance strategy which has the following advantages:
increased thermal exchange surface with the ambient inside the vehicle;less impact speed between the air and the passengers;less air flow noise.
When the conditions require, the climate control sytem control unit switches on the air cooling and dehumidification circuit, activating the air conditioning compressor    (Wiring Diagram ) E6021 COMPRESSOR ENGAGEMENT
The air recirculation condition causes the central closure of the windows Wiring diagram E3050 and E3051 FRONT ELECTRIC WINDOWS AND REAR ELECTRIC WINDOWS and the sun roof Wiring diagram E3060 SUN ROOF, using the specific signals sent to the Body Computer by the exhaust gas and rain/dusk sensors.The climate control system control unit acquires the signal from the exhaust gas sensor and activates the recirculation function to prevent the introduction of polluted air into the passenger compartment. When normal conditions are resumed, the climate control system control unit returns the recirculation to the position prior to the activation of the function.
The climate control system control unit receives information concerning the windscreen washer switched on by the Body Computer and activates the recirculation function to prevent the smell of the detergent liquid entering the passenger compartment.The 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.The Body Computer continuously acquires the battery voltage signal to compare it with a limit figure: if the battery voltage measured is below the level, it intervenes via the CAN sending a signal to disable a series of loads, including the fan. There is no strategy for switching off loads when the ignition is switched on.The following load exclusion strategy is managed at the key-off:

  • when the ignition is switched off a 15 minute timer is set after which the loads are deactivated;
  • the same 15 minute timed period is set when one of the doors is opened or a signal that the doors have been unlocked using the remote control is received;
  • if, another door is opened during the 15 minutes period or a command to unlock the doors using the remote control is received, the period in progress is reset and the timing begins again from 15 minutes;
  • at the end of the timed period, if one of the events described previously occurs, the timing starts again.