Procedure for operating a transmission device, particularly a 9-speed-transmission

A method of operating a transmission device (1) which can be transferred to various operating states by actuating shift elements (A to F), at least one of the shift elements (A, F) is a form-locking shift element which is transferred from an engaged operating state to a disengaged operating state in order to implement a defined operating state of the transmission device (1) during which a power flow between a transmission input shaft (2) and a transmission output shaft (3) is either present or is interrupted, a sensor device (22) is associated with the form-locking shift element (A, F), an operating state of the form-locking shift element (A, F) is determineable by the sensor device and, if there is a request to disengage the form-locking shift element (A, F), a disengagement control signal (IF) is generated and the form-locking shift element (A, F) is actuated in a direction of disengagement depending on the disengagement control signal, the method comprising the step of:

• transferring the transmission device (1) to a safe operating state, in which at least the transmission output shaft (3) can rotate, when an engaged operating state of the form-locking shift element (A, F) is determined by the sensor device (22) even though a disengagement control signal (IF) was generated.