Fan Speed Sensor (FSS)

The FSS is a Hall effect sensor integral to the cooling fan clutch. The PCM monitors the sensor input and controls the cooling fan speed based upon the engine coolant temperature, the transmission fluid temperature, and the intake air temperature 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.