Method for adapting a pressure characteristic line of a friction-locking shifting element of a transmission, and controller

A method for adapting a pressure characteristic curve (6) of a friction-locking shift element (1) of a transmission of a motor vehicle, a rapid filling time of the friction-locking shift element (1) being adapted to an adapted rapid filling time (tSF) for a rapid filling pressure (pSF) via a rapid filling time adaptation of the friction-locking shift element (1), a reaction of the transmission to the rapid filling time adaptation being ascertained, the method comprising:

• a) selecting a characteristic point (TP;
• CP) to be adapted on the pressure characteristic curve (6) when the friction-locking shift element (1) is actuated for engagement using the rapid filling pressure (pSF) for an actuation duration which is shorter than the adapted rapid filling time (tSF) by a defined period of time (ΔtTP;
• ΔtCP);
• b) actuating the friction-locking shift element (1) towards engagement using the rapid filling pressure (pSF) for a first time duration (tSF-ΔtTP;
• tSF-ΔtCP), the first time duration being shorter than the adapted rapid filling time (tSF) by the defined period of time (ΔtTP;
• ΔtCP);
• c) actuating the friction-locking shift element (1) using a waiting pressure (pW) for a waiting time duration (ΔtW), the waiting pressure (pW) being lower than the rapid filling pressure (pSF), the waiting time duration (ΔtW) being subsequent to the first time duration (tSF-ΔtTP;
• tSF-ΔtCP);
• d) actuating the friction-locking shift element (1) using the rapid filling pressure (pSF) during a second time duration and ascertaining a reaction of the transmission to adaptation, the second time duration being equal to the defined period of time (ΔtTP;
• ΔtCP), the second time duration being subsequent to the waiting time duration (ΔtW);
• and
• e) determining, when the reaction of the transmission to the adaptation corresponds to the reaction of the transmission to the rapid filling time adaptation, a pressure to be adapted at the characteristic point (TP;
• CP) on the pressure characteristic curve (6) as the waiting pressure (pW).