Engine Over-Temperature Warning Indicator
WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
The engine over-temperature status is determined by the cylinder head temperature sensor, which is hardwired directly to the PCM. The status of the cylinder head temperature is sent from the PCM over the communication network to the instrument cluster. The instrument cluster then determines whether or not the cylinder head temperature is above the over-temperature threshold.