F 350 2WD Super Duty V8-6.4L DSL Turbo (2009)
Radiator Cooling Fan Speed Sensor: Description and Operation
ENGINE CONTROL COMPONENTS
Fan Speed Sensor (FSS)
The FSS is a Hall effect sensor integral to the cooling fan. The PCM monitors the sensor input and controls the cooling fan speed based upon the
engine coolant temperature (ECT), the transmission fluid temperature, and the intake air temperature (IAT) requirements. When an increase in cooling
fan speed for vehicle cooling is requested, the PCM monitors the FSS signal and outputs the required pulse width modulation (PWM) signal to a fluid
port valve within the cooling fan.
