Electric Cooling Fan Control Module
The electric cooling fan is installed in the front of the Air Conditioning (A/C) condenser. The electric cooling fan is operated by the electric cooling fan control module which is integrated into the electric cooling fan motor. The PCM controls the electric cooling fan control module through a Pulse Width Modulation (PWM) signal.
The electric cooling fan control module is provided with:
- Power supply from the Engine Junction Box (EJB)
- Ignition signal from the PCM relay in the EJB
- PWM signal from the PCM
- PCM Ground.
To control the electric cooling fan, the PCM varies the duty cycle of the PWM signal. The cooling fan control module translates the duty cycle into a fan target speed and sets the output current to the cooling fan motor accordingly.
The PCM varies the duty cycle of the PWM signal between 0% and 100% to operate the electric cooling fan motor in 1 of 4 modes:
- Off.
- Minimum speed (750 Revolutions Per Minute (RPM)).
- Linear variable speed between minimum and maximum speeds.
- Maximum speed (2, 820 RPM).
The engine cooling fan control module incorporates a temperature sensor to prevent damage caused by excessive heat at high ambient temperatures. Operation of the engine cooling fan control module is discontinued if the temperature reaches 135°C (275°F). Operation resumes when the temperature decreases to 120°C (248°F).
For additional information, refer to: ENGINE COOLING