Originally Posted by sbchris
...the problem sensor mentioned in the manual. The problem with some of the newer Ford vehicles is the sensor is a multi stage sensor, which mean the sensor resets at a certain temperature and increases in voltage then starts dropping again.
This is incorrect, on several levels. That's not an engine coolant temperature sensor (ECT); it's a cylinder head temp sensor (CHT), which is different. And that step in voltage doesn't occur within the sensor; it occurs within the PCM. Read this caption: