An electronic system to operate an electromechanical parking brake for a land vehicle comprises at least one input unit to detect a driver request for parking brake and at least two control units in connection with the input unit to evaluate the driver request for parking brake transmitted thereto. The control units are in connection with at least one actuator for activating the parking brake, in order to control said actuator. In addition, the system comprises an energy supply to feed the input unit, and the control units of the at least one actuator. On occurrence of a single fault from a set of possible fault states in the system, at least one control unit and at least one actuator are supplied with energy and/or control signals, the at least one control unit supplied controls the at least one actuator supplied so that the land vehicle is fixed in a parked position when a corresponding driver request for parking brake is present.