IHKS Principle Of Operation
Blower
When KL 15 is switched "ON", the blower is activated in linear progression from 0 to 8 Volts (depending on the selected blower speed). When the blower is switched "OFF" (zero position) the IHKS is deactivated in addition to the following
- Blower switched off
- Fresh air/recirculating air flap closed
- Mixed air flap closed (to ensure the heat exchanger does not unnecessarily heat up the heater/air conditioner)
- Compressor switched off
Note. Rear window defogger can still be activated
Scheme 77
Warm and cold air are mixed for temperature control. The requested temperature is set by the rotary knob on the control panel/control unit. The outlet temperature is set by a stepper motor coupled to the mixed air flap.
The temperature is controlled by mixing
- Outside air that flows through the evaporator = cold air
- Outside air that initially flows through the evaporator and then through the heat exchanger (reheat) = warm air
Note. Changes in engine RPM do not trigger any temperature adjustments.
Air Distribution
The individual setting for the air distribution is requested with the rotary knob on the control panel. The main flap settings are
"Defrost"
"Ventilation"
"Footwell"
Scheme 78
The central kinematics stepper motor adjusts the cam disc for air distribution.