I've been told that my 5.4 has three coolant sensors.
I don't need the sending unit, my dash gauge works OK.

I need the sensor that monitors the coolant temperature as the engine warms up. It allows the the RPMs to run higher while the cold engine heats up....then after a certain point (usually about 4 miles of driving) the RPMs return to normal.

example: cold engine at 70 mph runs at 2300-2500 RPMs
After it reaches the operating temperature it returns to 2000-2100 rpm's.

What I have noticed is that it takes longer for it to heat up. So I want to replace whatever sensor that controls this task. And I need to know where it is at. Thanks for any help.

 

Check the thermostat first.

 

I will replace the thermostat regardless, but I'm still looking for the coolant temp sensor.

 

You don't have an engine coolant temp (ECT) sensor, you have a cylinder head temperature (CHT) sensor.

The CHT sensor doesn't control the warmup cycle (the thermostat does that), it reports it to the PCM which is then able to make other engine management decisions based on that and other inputs.

Your example of is not a function of the engine warmup cycle, it's due to overdrive being inhibited until the TFT sensor reports that the transmission fluid has reached its minimum operating temp for overdrive operation.

 

projectSHO89.....thanks for the information about the TFT sensor. It makes more sense to me now that I know why my engine runs at higher rpm's when it is really cold outside.

My 2012 Fusion with the 2.5L does the same thing when it is cold.