Vehicle Speed Sensor
WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2000 Mercury Villager, 2000 Mercury Mountaineer, 2000 Lincoln Navigator, 2000 Ford Windstar, and 2000 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
The vehicle speed sensor (VSS) is a variable reluctance or Hall-effect sensor that generates a waveform with a frequency that is proportional to the speed of the vehicle. If the vehicle is moving at a relatively low velocity, the sensor produces a signal with a low frequency. As the vehicle velocity increases, the sensor generates a signal with a higher frequency. The PCM uses the frequency signal generated by the VSS (and other inputs) to control such parameters as fuel injection, ignition control, transmission/transaxle shift scheduling and torque converter clutch scheduling.