Input device for a motor vehicle with voltage-based error detection

An input device for safety-relevant functions of a motor vehicle, comprising:

• a switch element, which has a switch contact with a first connection and a mating contact with a second connection, wherein the switch contact is configured to make contact with the mating contact when the input device is actuated;
• a first resistor, with a first and second voltage supply connection via which an operating voltage for the input device is provided, wherein the first voltage supply connection is connected to one of the connections of the switch element and the second voltage supply connection is connected via the first resistor to the other connection of the switch element;
• a measuring node provided between the first resistor and the associated connection of the switch element and which is connected to a measuring connection, so that an actuation-dependent voltage, which is dependent on the actuation of the input device, is detected via the measuring connection,
• wherein the switch element has a third connection which is connected to the switch contact, wherein a second resistor is provided which is connected to the second and third connections of the switch element so that, in the event of a fault of the switch contact, or a break of the switch contact, an error voltage is detected at the measuring node via the measuring connection and is distinguished from the actuation-dependent voltage;
• and
• an evaluation circuit configured to detect the voltage at the measuring node via the measuring connection and thereby identify an actuation of the input device and/or a fault of the switch contact,
• wherein the switch contact is rounded or dome-shaped and the first and third connections are provided in opposite regions of the rounded or dome-shaped switch contact.