15
2001 model year changes
IHKR control unit with operating controls
The IHKR control unit is incorporated into the control panel. The control panel consists of
three buttons and three rotary dials.
Functional Description:
Air distribution:is carried out using the mechanical rotary dial acting on three
bowden cables.
Blower adjustment:is carried out using the rotary dial potentiometer (22 steps). The
control unit signals the final stage via a variable voltage signal.
Temperature control: The desired interior temperature is set with the rotary dial
potentiometer on the control panel. Temperature regulation is based on the Y-factor.
The inputs used to determine the Y-factor are:
Position of the temperature control potentiometer dial
Heater core temperature
Coolant temperature
Exterior Temperature
Interior Temperature
Control of the interior temperature is carried out by the control unit cycling the water
valve to regulate the temperature of the heater core. During heater operation the
auxiliary water pump will be switched on to increase coolant circulation through the
heater core. The service station feature is carried over to the E39 IHKR.
Fresh air/recirculation:Recirculation is requested by an input to the control panel
button or the MFL. The control unit actuates the fresh air/re-circ stepper motor for
control of the flap position. Ram effect air is compensated for.
Air conditioning: :
The request for air conditioning is made by means of a push button.
X611 X610
12 pin 26 pin
X18341
3 pinBlue - vent flaps
Red - defrost flaps
Green - footwell flaps3 cables1. Temperature control potentiometer
2. Air distribution mechanical knob
3. Fan control potentiometer
123
4
5
6
4. Recirculation
5. Air conditioning request
6. Rear window defroster
