SETTABLE UNIT FOR INSTALLATION IN OR ON A VEHICLE

An adjustable exterior mirror on a vehicle, or another kind of settable unit for installation in or on the vehicle, signals a sensor signal via the current through the current conductors for the supply current of a motor, heating or other function holder in the vision unit. In response to external switching-on of a supply voltage between the current conductors, for example from the vehicle, an aspect of the current is sensor-dependently controlled from the settable unit. In the vehicle, the aspect of the current through at least one of the current conductors is measured during a delay time interval after switching-on of the supply voltage to read out the sensor result.