HEATER - Description

Description

The vehicle climate control system involves a duct/distributor unit with a heater.

The climate control is operated by acting on the three knobs in the dashboard:

• the left knob controls mixing of hot and cold air;
• the right knob, mechanically operated via a cable, controls the opening of the flaps which regulate the distribution of air flows;
• the centre knob electrically controls the ventilation of the air at four different speeds;
• the right button switches on the heated rear windscreen; the LED comes on when the button is pressed.See E3030 HEATED REAR WINDSCREEN AND DOOR MIRROR DEFROSTING.
• When pressed, the central button activates the air recirculation function; when the button is pressed the LED comes on. If the button is not pressed, dynamic air is taken in from ouside due to the car's motion.

A dedicated control unit manages system operation by controlling:

• Air distribution to the vents.
• speed of the fan (varies continuously);
• activation of air recirculation;

The control unit sets the above parameters in order to adjust passenger compartment temperature to the required level. According to the setting, the control unit adjusts passenger compartment air intake speed by means of the fan motor and air temperature by a mixer actuator. It also controls flow distribution via another actuator and - lastly - the interior/exterior air recirculation function via a final actuator.

For more details Characteristic of working principle 5020 HEATER.

The body computer continually downloads a battery voltage signal for comparison with its limit value. If the recorded battery voltage is lower than the threshold, the computer cuts in via the CAN network to send a signal to disable a series of appliances: this includes the fan control.

The climate control system ECU is supplied by an ignition-operated line protected by a fuse in the underfacia control unit; the fan is supplied by a line protected by a specific engine bay control unit fuse.