Turbine Shaft Speed (TSS) Sensor
WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
The turbine shaft speed (TSS) sensor is a magnetic pickup, that sends a signal to the PCM to indicate TSS. The TSS is mounted externally on the case. The PCM uses the TSS signal to help determine appropriate operating pressure and TCC operation.