DTC P0744 A/T TCC S/V Function (Lock-Up): Description

WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.

This malfunction will not be detected while the O/D OFF indicator lamp is indicating another self-diagnosis malfunction.
This malfunction is detected when the torque converter clutch does not lock up as instructed by the TCM.
This is not caused by electrical malfunction (circuits open or shorted) but by mechanical malfuction such as control valve sticking, improper solenoid valve operation, malfunctioning oil pump or torque converter clutch, etc.