a method for regulating an automatic transmission unit having a plurality of coupling devices includes supplying a hydraulic medium to a control element ; and supplying at least a portion of the hydraulic medium to a hydraulic regulating valve . the control element determines the portion of the hydraulic medium supplied to the hydraulic regulating valve and supplies that portion to the hydraulic regulating valve . the hydraulic regulating valve regulates an operational function of one of the coupling devices . when the central element fails , a safety device regulates the operational function of one of the coupling devices as a function of the revolution speed of a shaft of an engine .