3 Series E92 330xi (N52K) COUPE
Brief description of components
The following components send signals to the auxiliary heating system:
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Telestart transmitter
The Telestart transmitter sends the signal to switch the auxiliary heating on and off to the CAS control unit.
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Temperature sensor in auxiliary heater circuit
The temperature sensor in the auxiliary heater registers the temperature in the heating circuit. The signal is
processed in the control unit for the auxiliary heater. The control unit therefore controls full-load operation, part-
load operation and control pause.
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Temperature sensor for overtemperature protection
The temperature sensor in the auxiliary heater registers the operating temperature. The overtemperature
protection facility protects the auxiliary heater from impermissibly high operating temperatures.
The following control units are involved in the auxiliary heating system:
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IHKA control panel and IHKA control unit
The IHKA controls and the IHKA control unit are combined in a single component.
The IHKA control unit is connected to the K-CAN and LIN bus.
The IHKA control unit outputs all the requests for the independent heating function as a message on the K-CAN
and the LIN bus.
A flashing symbol in the display indicates when the independent heating is in operation.
From terminal R it is possible to specify the desired interior temperature for the independent heating function
during independent heating operation at the IHKA controls. The set temperature is shown in the display of the
IHKA control panel.
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JBE: Junction box electronics
The JBE is an integral part of the junction box. The junction box consists of the JBE and the power distributor.
The power distributor provides the power for the auxiliary heater.
The JBE is connected via the K-CAN to the bus system.
> E70
Note: The JBE controls the water valve for metering the throughflow of coolant to the heat exchanger.
The water valve works electromagnetically and meters the coolant flow rate to the heating system heat
exchanger as it is needed. This determines the temperature of the air used for heating the vehicle interior.
In the case of automatic air conditioning with separate adjustment for the driver and passenger sides, a duo
water valve is installed on account of the left/right separation of the heat exchanger.
> E90, E91, E92, E93
Note: The JBE controls the water valve and the auxiliary water pump.
The water valve controls the supply to the independent auxiliary heater either from the radiator supply or
from the heat exchanger return flow.
In the E70 the switchover valve controls the supply to the independent auxiliary heater.
Activation is effected on the prompt of the IHKA control unit via the K-CAN.
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CAS: Car Access System
The Telestart receiver receives the radio signals from the Telestart transmitter and forwards them to the CAS
control unit. In turn, the CAS control unit sends a message on the K-CAN.
Signal path: Telestart transmitter -> Telestart antenna -> Telestart receiver -> direct wire -> CAS -> K-CAN ->
IHKA control unit -> LIN bus -> SHZH control unit
SBT Independent heating E70, E90, E91, E92, E93
BMW AG - TIS
14.02.2013 10:05
Issue status (12/2007) Valid only until next DVD is issued
Copyright
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