Patent ID: 7719402

Claim:
A diagnostic circuit for a potentiometer, the diagnostic circuit comprising: a laminated plate; at least one supply track; at least one resistance track, which has a track beginning and a track end, whereby located between the track beginning and the track end is a transition area, over which a contact slider of the potentiometer moves; a microprocessor having a first input that is connected to the contact slider of the potentiometer; and a resistor that is electrically connected to the contact slider of the potentiometer and that is directly electrically connected to a second input of the microprocessor, wherein a contact resistance that is present at the slider during adjustment of the slider is measured in a cyclical measurement step and compared in the microprocessor with stored control values, and wherein, during the measurement step, the contact resistance is measured by the microprocessor in an unloaded state, in a loaded state with a supply voltage, and against a ground.