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Electric auxiliary heater

The electric auxiliary heater is a separate component and is installed in the heating and air-conditioning unit. The electric auxiliary heater consists of 4 heat registers. The heat registers are the heat exchange elements of the electric auxiliary heater. Each heat register contains 1 heating element. Air is heated directly by these heating elements and is then fed through the air vents into the passenger compartment. In principle, the electric auxiliary heater works like an electric radiator.

The electric auxiliary heater accelerates the heating of the passenger compartment, especially at low ambient temperatures and during the cold-start phase.

The electric auxiliary heater is activated by the control unit of the integrated automatic heating and air-conditioning system (IHKA control unit). Depending on different signals (e.g. temperature signal from the rear footwell temperature sensor, signals from energy management), a percentage power request for the electric auxiliary heater is generated in the IHKA control unit and sent on the LIN bus

Fig 1: Identifying Electric Auxiliary Heater Parts
G09872694Courtesy of BMW OF NORTH AMERICA, INC.
Item Explanation
1 Heating element
2 Connection of the load earth (for heating elements and electronics)
3 Connection of voltage supply for the heating elements
4 Connection for the LIN bus