Output Shaft Speed (OSS) Sensor
WARNING: This page is about a different car, the 1995 Ford Windstar. However, it is still accessible from the selected car via links, so may be relevant.
The OSS sensor is a magnetic pick-up. It sends a voltage signal to the PCM. This signal tells the PCM transmission output shaft speed RPM. The signal is also used for shift schedules and modulated converter clutch control.
OSS is located on the rear of transmission case on driver's side of vehicle. Control functions associated with OSS are limiting vehicle speed, converter clutch control and shift quality.