The nominal value for the interior temperature is set with the temperature control wheels. The temperature values printed on the control wheels of the operating unit do not correspond to the values which are used by the control unit and which can be read out via the status list. The values correspond to a temperature which the driver perceives as comfortable.
The positions are detected by the potentiometer resistors in the control wheels. The water valves are closed in the minimum position (cold) and opened in the maximum position (warm).
The defrost feature has a priority function in air distribution and in the control calculation for heating. The defrost function is activated by means of the defrost stage (5th stage) in the blower switch.
At an outside temperature below 10 o C, the water valves are forced open.
If the outside temperature exceeds 10 o C, the nominal temperature value for the driver's and passenger's side is increased by 1 o C. At the same time, the nominal heat exchanger value is increased by at least 30 o C.
An electrical auxiliary water pump is installed in order to ensure adequate water flow through the heat exchanger at low engine speeds. This water pump ensures virtually constant speed-independent water flow through the heat exchanger.
The auxiliary water pump is switched on at:
The auxiliary water pump is switched off at: