3 Series E90 316i (N45) SAL
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Evaporator (IHKR, IHKA only)
The evaporator plates are cooled by the refrigerant that has been evaporated inside the evaporator. The airflow
generated by the blower is fed over the cooled evaporator plates. The air is cooled and dried and fed into the
vehicle.
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Auxiliary water pump
The auxiliary water pump serves to make sure that the coolant flow rate needed in the heater circuit is
maintained, even at low engine speeds. The auxiliary water pump is actuated by the junction box, from which it
also draws its power supply. The IHR/IHKR/IHKA control unit emits the signal for switching the auxiliary water
pump on/off (via the K-CAN).
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Water valve
> E70
The water valve works electromagnetically and meters the coolant flow rate to the heating system heat
exchanger as it is needed. This regulates the air temperature for heating the vehicle interior (heating and air
conditioning that regulates water temperature).
On the IHKA High, a dual water valve is used for the left/right separation of the heating system heat exchanger.
The JBE controls the water valve.
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Radiator fan
Besides the engine cooling, the radiator fan is also needed for cooling the condensers. The radiator fan is
actuated by the DME/DDE.
Signal path:
IHKR or IHKA control unit -> K-CAN -> Junction box electronics (serves as data interface) -> PT-CAN ->
DME/DDE -> Radiator fan
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Condenser with integrated dehumidifier flask (IHKR, IHKA only)
Refrigerant is converted from gas into liquid in the condenser. In the integrated drier flask, which is installed
downstream of the condenser, any water that may be present in the refrigerant circuit is collected. The drier
element can be exchanged.
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Expansion valve (IHKR, IHKA only)
The expansion valve controls the injection quantity into the evaporator. Only as much liquid refrigerant enters the
evaporator as the evaporator is able to completely evaporate. Drops of liquid that have not been evaporated
would cause damage in the A/C compressor.
The expansion valve is fitted directly to the engine compartment bulkhead.
Additional components:
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Microfilter
Fresh air for interior ventilation is fed through a microfilter.
> E81, E82, E87, E90, E91, E92, E93: IHR, IHKR
When a filter replacement is needed, this will be indicated by the Condition Based Service (CBS) (until 03/2007).
from 03/2007: Filter replacement: see Service Booklet
> E70: IHKA
Filter replacement: see Service Booklet
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Microfilter with activated charcoal
On the IHKA, a microfilter with activated carbon is fitted. The activated-charcoal filter helps to provide additional
purification of the incoming fresh air from gaseous pollutant emissions.
> E81, E82, E87, E90, E91, E92, E93: IHKA
When a filter replacement is needed, this will be indicated by the Condition Based Service (CBS) (until 03/2007).
SBT Integrated heating control and air-conditioning system E70, E81, E82, E87, E90,
BMW AG - TIS
18.01.2013 20:03
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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