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Home >> BMW >> 2013 >> 528i >> Repair and Diagnosis (Single Page) >> General Information >> OEM General Information >> Functional Description - F10 - HVAC System, Steering System, Restraints System >> HVAC System - Functional Description >> Integrated automatic heating/air conditioning system (IHKA) >> HKA control unit and control panel
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HKA control unit and control panel

The control panel and control unit are installed separately. The control unit of the rear automatic air conditioning (HKA control unit) is installed on the rear air conditioner. The HKA control unit activates the mixing flap drives, the air distribution flap motors, the light-emitting diodes, as well as the blower of the rear air conditioner by means of an output stage.

The left-right separation means that the rear air conditioner has 2 control panels (left-hand control panel on the rear air conditioner and right-hand control panel on the rear air conditioner). A control panel is installed each roof air vent.

The control panels regulate the air supply and air temperature (only cooling possible) in the rear passenger compartment via the two roof air vents.

The left-hand control panel on the rear air conditioner is connected directly via a plug connection to the right-hand control panel on the rear air conditioner. This means that all the settings for the left-hand control panel on the rear air conditioner are picked up and digitized in the electronics of the right-hand control panel on the rear air conditioner. The right-hand control panel on the rear air conditioner sends the signals on the LIN bus to the HKA control unit.

Fig 1: Identifying HKA Control Unit And Control Panel
G09909900Courtesy of BMW OF NORTH AMERICA, INC.
Item Explanation
1 Temperature selector wheel (only cooling possible) in the right-hand control panel on the rear air conditioner
2 Button for manual variation of the amount of air and light-emitting diodes to indicate the selected amount of air on the right
3 adjuster knob to change the airflow direction on the right
4 Air outlet at roof air vent on the right
5 Temperature selector wheel (only cooling possible) in the left-hand control panel on the rear air conditioner
6 Button for manual variation of the amount of air and LEDs to indicate the selected amount of air on the left
7 adjuster knob to change the airflow direction on the left
8 Air outlet at roof air vent on the left