Radiator Cooling Fan Motor: Description and Operation
Engine Control ComponentsFan Control
The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure) to determine engine cooling fan needs.
For variable speed electric fan(s):
The PCM controls the fan speed and operation using a duty cycle output on the fan control variable (FCV) circuit. The fan controller (located at or integral to the engine cooling fan assembly) receives the FCV command and operates the cooling fan at the speed requested (by varying the power applied to the fan motor).
FCV Duty Cycle Output From PCM (Negative Duty Cycle):
For relay controlled fans:
The PCM controls the fan operation through the fan control (FC), (single speed fan applications), low fan control (LFC), medium fan control (MFC), and high fan control (HFC) outputs. Some applications will have the xFC circuit wired to 2 separate relays.
For 3-speed fans, although the PCM output circuits are called low, medium, and high fan control cooling fan speed is controlled by a combination of these outputs. Refer to the following table.
2.0L Focus (with A/C): PCM FC Output State For Cooling Fan Speeds:
2.5L Escape: PCM FC Output State For Cooling Fan Speeds:
