Vehicle Speed Sensor (VSS)
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2000 Nissan Xterra, 2000 Nissan Sentra, 2000 Nissan Quest, 2000 Nissan Pathfinder, and 2000 Nissan Maxima. However, it is still accessible from the selected car via links, so may be relevant.
VSS is a pulse generator, located in transaxle, which provides a vehicle speed signal to speedometer. Speedometer then sends a signal to ECM.