Smooth Lock Up Control: Notes
WARNING: This page is about a different car, the 2006 Nissan Xterra. However, it is still accessible from the selected car via links, so may be relevant.
When shifting from the lock up released state to the lock up applied state, the current output to the torque converter clutch solenoid is controlled with the TCM. In this way, when shifting to the lock up applied state, the torque converter clutch is temporarily set to the half-clutched state to reduce the shock.