air condition BMW 3 SERIES 2002 E46 Model Yar Changes

13
2001 model year changes
E39 IHKR
The 525i/it will be fitted with IHKR as standard
equipment. IHKA will be available as an option
on those vehicles by ordering the Convenience
package: SA 466.
IHKR is a semi-automatically regulated heating
and air-conditioning system. The components
are similar to the IHKR system used in the X5
3.0i.
The E39 IHKR is a single zone system that regulates the temperature of the cabin based
on the occupants desired temperature, selected by a temperature setting dial. Blower con-
trol, air distribution settings and stratification flap are manual.
System Components
The E39 IHKR consists of the following components:
 IHKR control unit with operating controls
 IHKR integrated heater and air conditioning case
 1 Heater core temperature sensor
 Evaporator temperature sensor
 Interior temperature sensor (located in drivers footwell)
 Double cage blower motor and final stage
 1 Water valve (duty cycle controlled)
 Auxiliary water pump
 1 Fresh air/re-circ stepper motor
 Auxiliary fan (DME controlled)
 Refrigerant Pressure Sensor
 Left and right fresh air micro-filters

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

19
2001 model year changes
Changes made to the E39 IHKA
 New Control Unit (since 9/00).
 Addition of solar sensor (since 9/00).
 New IHKA integrated heater and air conditioning case (since 3/00).
IHKA IV Control Unit
The “REST” button on the control unit has been
replaced with a “MAX” button. Two different functions
are carried out by pushing the MAX button:
 Maximum cooling function
 Residual heat function
Determination of which function will be enabled is
based on switching criteria.
A/C MAX function
(This feature was introduced in the E38 since 9/99)
Maximum cooling performance is automatically activated by pressing the MAX button. An
LED on the button illuminates to indicate that the function is active.
Criteria for operation:
Terminal 15 “on” , MAX button pressed and outside temperature above 60
oF.
The following settings are adjusted or activated:
 Temperature control is canceled and the temperature display indicates 60
o F.
 Both water valves are closed.
 The left and right Y-factors are set to -27.5%.
 The compressor is switched on (LED turns on in the A/C switch).
 The blower setting is set to maximum.
 Recirculation is activated (LED turns on in the re-circ switch).
 Air distribution is set to center vents only.
Operation of the max defrost is overridden by selecting MAX. The operation of the rear win-
dow defogger is not affected.

21
2001 model year changes
IHKA integrated heater and air conditioning case
The E39 IHKA case has been redesigned since 3/00. The E39 and E53 both share the
same case design.
The difference from the previous case is that a single flap (left and right), controls both the
fresh air and recirculation inlets. Ram air is controlled by a separate flap. What makes it
possible to use a single flap for fresh air/re-circ is the semi-circular door; as one inlet is cov-
ered another is opened.
Please refer to the Climate Control course material ST 054 for a complete functional description of
ram air pressure compensation.
1. Stepper motor for footwell
2. Stepper motor for rear compartment, stratification
3. Fresh air/recirculation flap
4. Output stage for blower motor
5. Stepper motor for ram air flap
6. Ram air flap
Stepper motors for the fresh air/recirculation,
defrost and ventilation flaps are located on the
left side of the housing
3
6
4
2
15
Right Side of IHKA IV Case
Ram air and fresh air/re-circ flaps as seen from the engine side of the bulkhead