Method for operating a lock with back-up device for locking and/or unlocking the lock

The device has a handle (20), a mechanism for interaction with the lock, a communications arrangement between the vehicle and an identification transmitter (40) of the authorized user to change the lock between an unsecured position and a secured position in which operating the handle is effective. The communications involves coded signals exchanged between at least two electronic components, one in the vehicle and one integrated in the identification transmitter. The portable identification transmitter is an active part of an emergency device whose current source (44) provides the energy for changing over an actuator (14) for releasing/securing the lock in an emergency situation.