Operation CHARM: Car repair manuals for everyone.
Do you have access to Mitchell1 Prodemand? If you are willing to share user/password (we can pay $250), please get in contact with us ASAP: email operation-charm [[at]] tuta.io or click to submit anonymously. (This is the last day we'll be asking)

Radiator Cooling Fan Speed Sensor: Description and Operation

ENGINE CONTROL COMPONENTS

Fan Speed Sensor (FSS)
The FSS is a Hall-effect sensor that measures the cooling fan clutch speed by generating a waveform with a frequency proportional to the fan speed. If the cooling fan clutch is moving at a relatively low speed, the sensor produces a signal with a low frequency. As the cooling fan clutch speed increases, the sensor generates a signal with a higher frequency. The PCM uses the frequency signal generated by the FSS as a feedback for closed loop control of the cooling fan clutch. For additional information on the cooling fan clutch, refer to the Cooling Fan Clutch.


Cooling Fan Clutch With FSS: