A method for operating an automatic transmission includes determining at least one of an elapsed time from adjusting a first one of at least one positive-locking shift element towards a closed configuration or a differential speed rotation of the first one of the at least one positive-locking shift element and shifting the automatic transmission to a substitute gear if the elapsed time from adjusting the first one of the at least one positive-locking shift element towards the closed configuration reaches or exceeds a time limit and/or the differential speed rotation of the first one of the at least one positive-locking shift element reaches or exceeds a rotational speed limit. A related transmission control device for an automatic transmission is also provided.