In a method for controlling a connection of a high-voltage source of a motor vehicle to a high-voltage network of the motor vehicle, first at least one test value for an electrical operating variable of the high-voltage network is determined by means of a control device of the motor vehicle after a connection command is received. The electrical operating variable depends on a capacitance actually effective at a connection of the high-voltage source to the high-voltage network. Only when the at least one test value meets a predefined safety condition, is a precharge current of the high-voltage source conducted via a first precharge resistor, which limits the precharge current, to the connection and into the high-voltage network to charge up a capacitor of the high-voltage network. Otherwise the precharge current is blocked.