Engine Over-Temperature Indicator
WARNING: This page is about a different car, the 2002 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
The cylinder head temperature sending unit is hardwired directly to the PCM. The status of the cylinder head temperature is sent from the PCM over the SCP communication network to the instrument cluster. The instrument cluster then determines whether or not the cylinder head temperature is above the over-temperature threshold.