P1778 Step Motor - Function: Description

WARNING: This page is about a different car, the 2009 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

The step motor changes the step by turning 4 coils ON/OFF according to the signal from TCM. As a result, the flow of line pressure to primary pulley is changed and pulley ratio is controlled.
This diagnosis item is detected when the electrical system is OK, but the mechanical system is NG.
This diagnosis item is detected when the state of the changing of the speed mechanism in the unit does not operate normally.