DTC P0720: Vehicle Speed Sensor A/T (Revolution Sensor): Description
WARNING: This page is about a different car, the 2005 Infiniti FX45 and 2005 Infiniti FX35. However, it is still accessible from the selected car via links, so may be relevant.
The revolution sensor detects the revolution of the idler gear parking pawl lock gear and emits a pulse signal. The pulse signal is sent to the TCM which converts it into vehicle speed.