General System Description

ECC Operating Chart. Read the chart sa follow, select the symbol corresponding to the particular setting at the top of the table. The column directly underneath shows the actual or possible settings of the various components shown at the left of the chart.

NOTE:* If max. cooling is selected, recirculation will be engaged to achieve faster cooling (although never in the defroster position).

- "0-5" indicates the blower settings (the setting is steplessly variable in the automatic position).
- "1" indicates "Open"/"On".
- "0" indicates "Closed"/"Off".
- "0/1" indicates either 0 or 1, depending on other selected settings or whether the blower is on automatic.

Control Module Response To Faults:
- If a fault is detected, the control module will ignore the incorrect signal and will select a preset value which will make the best of the situation.
- If, for example, the servomotor potentiometer is faulty, the air mixing shutter will assume the position corresponding to the temperature selector.
- If the servomotor does not operate due, for example, to seizure of the arm or loss of the motor supply, the motor will be switched out after 10 seconds and will be prevented from restarting until the ignition is next switched on.
- If the blower motor or servomotor is connected to the incorrect supply voltage, the unit in question will be switched out immediately.
- In the event of a blower motor fault, starting of both the blower and compressor will be inhibited.





Override Control In Certain Cases:
- If the defroster setting is selected, A/C will be engaged in all cases if the ambient temperature is at least +5 °C (41 °F) and recirculation is deselected.
- If max. cooling is selected (and A/C is engaged), recirculation will be engaged in all cases, except when the defroster setting is selected.
- If max. cooling or max. heating is selected, the blower will run at max. speed in all cases if the blower selector is set to auto.
- If the 0 blower speed setting is selected, the A/C compressor will be switched out to prevent icing of the evaporator.
- At high vehicle speeds, the control module reduces the blower speed to provide a constant air flow inside the car. (Under these conditions, air is forced into the car by the ram action' of the air in front of it.) This applies to all blower settings, but not at max. cooling, max. heating or recirculation.
- Compressor switch-in is delayed for 10 seconds when the engine is started. This is to prevent stalling of the engine before the speed has stabilized. (However, the A/C button will be illuminated after 2 seconds.)

Special Functions:
- The control module will substitute a preprogrammed value for a missing or incorrect parameter.
- The control module will restart the program if it should crash'. (This may be caused by the effects of external interference on the electronics).





Parking Heater Input. The control module is provided with a special input for use when a parking heater is installed. When the parking heater is started, the climate unit is automatically set as follows:
- blower between settings 1 and 2
- floor/defroster
- max heat