Turbine Shaft Speed (TSS) Sensor
WARNING: This page is about a different car, the 2010 Lincoln Town Car. 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.