Engine Cooling Fan Control Module

The engine cooling fan control module is located on the rear of the engine cooling fan shroud.

The electric cooling fan is installed in a shroud which is attached to the rear of the radiator and secured with three screws. The electric cooling fan is operated by the engine cooling fan control module. The engine cooling fan control module is integrated into the electric cooling fan. An electrical connector at the right side of the shroud provides the interface between the cooling fan harness and the vehicle wiring.

The engine cooling fan control module is controlled by the Powertrain Control Module (PCM) via a Pulse Width Modulation (PWM) signal. A permanent startup battery voltage is supplied from the Battery Junction Box (BJB).

The PCM varies the duty cycle of the PWM signal between 0% and 100% to operate the electric cooling fan motor in one of four modes:

Off.

Minimum speed - 750 Revolutions Per Minute (RPM).

Linear variable speed between minimum and maximum speeds.

Maximum speed - 2820 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).

In the event of the engine cooling fan control module failure any of the following symptoms may be observed:

Increased engine operating temperature.

Incorrect engine cooling fan operation resulting in the engine over heating.

Reduction in Air Conditioning (A/C) performance.

Reduced engine performance and fuel economy.