The engagement and disengagement on the lock-up clutch is determined by the direction the fluid enters the torque converter. The automated transmission fluid can enter either throughout the front of the lock-up clutch or between the impeller and turbine, powering the clutch. To find out more regarding the torque converter, https://torque-converter-clutch52738.shotblogs.com/everything-about-torque-converter-clutch-48181134