Slip Lock-up Control

WARNING: This page is about a different car, the 2011 Nissan Armada. However, it is still accessible from the selected car via links, so may be relevant.

In the slip region, the torque converter clutch solenoid current is controlled with the TCM to put it into the half-clutched state. This absorbs the engine torque fluctuation and lock-up operates from low speed.
This raises the fuel efficiency for fourth and fifth gears at both low speed and when the accelerator has a low degree of opening.