DTC P0841: Pressure Sensor Function: Description
WARNING: This page is about a different car, the 2003 Nissan Murano. However, it is still accessible from the selected car via links, so may be relevant.
Using the engine load (throttle position), the primary pulley revolution speed, and the secondary pulley revolution speed as input signal, change the operating pressure of the primary pulley and the secondary pulley and change the groove width of the pulley to control the gear ratio.