General

Operation
FHK is an automatic climate control system in the rear area of the car which can only be installed in conjunction with the IHKA system. The heater is supplied on the water side. separated by a water valve from the front coolant circuit. Climate control takes place in parallel with respect to the IHKA, and both control units are coupled with an FHK relay box. Temperature mixing takes place separately on the left and right sides, dependent on the position of the temperature control wheels and of the mixing control, through the mixing flaps for ventilation as well as through footwell flaps for the footwell. Before the FHK control unit switches off after approximately 3 minutes ignition "OFF" and its power consumption reduces, the ventilation mixing flaps are set to the setting 50% "WARM" and the footwell flaps to "CLOSED".

Control Panel:

Control Panel

General Block Diagram:

General Block Diagram