Ambient Sensor
WARNING: This page is about a different car, the 2015 Nissan Murano. However, it is still accessible from the selected car via links, so may be relevant.
Ambient sensor measures ambient air temperature. The sensor uses a thermistor which is sensitive to the change in temperature. The electrical resistance of the thermistor decreases as temperature increases.
Courtesy of NISSAN NORTH AMERICA, INC.