Torque Converter Clutch Solenoid Valve
WARNING: This page is about a different car, the 2002 Infiniti QX4, 2001 Nissan Pathfinder, and 2001 Infiniti QX4. However, it is still accessible from the selected car via links, so may be relevant.
Torque Converter Clutch (TCC) solenoid valve is controlled by TCM. Solenoid is closed when off. TCC piston is designed to slip to adjust ratio of engagement, reducing lock-up shock.