F 150 2WD V8-5.4L Flex Fuel (2008)
Engine Temperature Sensor: Description and Operation
CHT Sensor
The CHT sensor:
^
is mounted to the wall of the cylinder head and is not connected to any coolant passages.
^
sends the PCM a signal indicating cylinder head temperature.
^
As the cylinder head temperature rises above normal operating temperature, the PCM will turn on the high speed cooling fan. If the
temperature continues to rise, the PCM will selectively and alternately disable fuel injectors. The cylinders that are not being fuel injected
will act as air pumps to aid in engine cooling. The PCM will also turn on the check engine light and set a DTC. If the cylinder head
temperature continues to rise, the check engine light will begin to flash and an additional DTC will be set. Finally, if the cylinder head
temperature rises still more, the PCM disables all of the fuel injectors, turning the engine off.