Engine Cooling Fan (FC) / Engine Cooling Fan (FC) Control Module
The engine cooling fan may have a post-run of up to approx. 6 minutes after the engine has been turned off. The time for the fan's post-run depends mainly on the temperature of the coolant.
Be careful since the engine cooling fan may have a post-run after the engine has been turned off.
The engine cooling fan consists of one or two fans and control module with an output for each fan. The control module is controlled by a signal from the engine control module (ECM).
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 modules. The control modules then activate the fans at different speeds. The speed is determined by the engine control module (ECM), depending on the coolant temperature and the vehicle speed.
The temperature conditions for engagement of the different engine cooling fan (FC) stages may vary slightly, depending on the engine variant and the equipment level. The temperature conditions apply when:
- the A/C is off
- no faults are detected by the Engine Control Module (ECM).
The engine cooling fan is placed behind the radiator and its control module is connected to the main wiring loom and is feed with voltage from the battery via a fuse. Some versions have a relay controlled by the system relay which cuts the current to the fan a while after start.
There are diagnostics for the engine cooling fan (FC). The engine cooling fan (FC) transmits a diagnostic signal to the engine control module (ECM).