Abstract: A method, by a control device, to activate an active discharge circuit to discharge a capacitive energy storage of at least one electrical consumer of an on-board power supply for a motor vehicle. An energy source for the on-board power supply can be coupled to the on-board power supply and be disconnected from the on-board power supply by a switching device. The control device receives a signal (S) for activating the active discharge circuit, examines, after receiving the signal (S), if the energy source is disconnected from the on-board power supply according to at least one first criterion, and activates the active discharge circuit only upon satisfaction of a condition that the energy source has been disconnected from the on-board power supply according to the at least one first criterion.