Radiator Cooling Fan: Description and Operation

Engine Cooling Fan (FC)/Engine Cooling Fan (FC) Control Module







The engine cooling fan (FC) has two functions. One is to cool the engine compartment, the other is to cool the condenser when the air conditioning (A/C) compressor is working.

The engine control module (ECM) transmits a pulse width modulated (PWM) signal to the engine cooling fan (FC) control module. The control module then activates the fan at different speeds. The speed of the engine cooling fan (FC) is determined by the engine control module (ECM), depending on the coolant temperature (based on the signal from the engine coolant temperature (ECT) sensor) and the vehicle speed.

When the vehicle is stationary, the engine cooling fan (FC) is activated as follows:
- the first stage is activated at approximately 105 degree C and shut of at approximately 100 degree C
- the second stage is activated at approximately 110 degree C and shut of at approximately 105 degree C
- the third stage is activated at approximately 115 degree C and shut of at approximately 110 degree C.

WARNING: The engine cooling fan (FC) may start itself for some time after the engine has been switched off. This is normal.

The engine cooling fan (FC) and its control module are behind the radiator.

The engine control module (ECM) can diagnose the engine cooling fan (FC). The fan can be activated using VADIS.