Engine Coolant Temperature Gauge
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 PCM receives the engine coolant temperature status through hardwired circuitry from the cylinder head temperature sensor. The instrument cluster receives the engine coolant temperature data from the PCM over the high speed CAN. The instrument cluster monitors the engine coolant temperature data received from the PCM and commands the engine coolant temperature gauge pointer.