DTC P0715 Input Speed Sensor Circuit (PRI Speed Sensor): Description

WARNING: This page is about a different car, the 2008 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.

The input speed sensor (primary speed sensor) is included in the control valve assembly.
The input speed sensor (primary speed sensor) detects the primary pulley revolution speed and sends a signal to the TCM.