BMW 17427545366 Radiator Cooling Fan Motor

Use a BMW factory scan tool or equivalent to read and clear fault codes, then switch the ignition OFF. Remove the intake air duct and the splash shield from under the engine. For automatic transmission, remove the fastener and take out the ATF cooler from the fan shroud, then detach the electrical connector and unclip the line from the fan cowl. Detach the cable strap and remove the fastener. For turbo models, release the charge air duct from the rubber mount on the fan cowl. Unlock the clip on the lower edge of the fan cowl and lift the electric fan and cowl out of the engine compartment. Installation is the reverse of removal, ensuring that the fan cowl snaps securely into the clips on the lower edge and that the fan electrical connector snaps firmly into place with the wires and hose routed as before.

The cooling fan is on the engine side of the radiator, and utilization is governed by the ECM through the output final stage which is on the fan housing near to the fan motor. The fan is controlled with a pulse width modulated signal and for wiring the circuit high-amp fuse is used. Turning on the electric fan requires signals with the ECM such as the radiator outlet temperature, computed temperature of the catalytic converter, speed of the vehicle, voltage in the battery, and the required refrigerant pressure. The electric fan is turned on at this phase by the ECM at20% of its maximum standard to enable some diagnostic procedures before being turned off immediately the vehicle is started. To operate in harmony, the voltage that is produced by the fan at the time of deceleration should match the rpm values that is stored in the fan output stage. If the ECM has stored any cooling fan fault it should be checked that the fan is not jammed and can rotate freely. If the air conditioner is switched on, then the electric fan does not start at once and after the switch-off of the engine, the fan might run at variable speeds for a period of up to 10 minutes depending on catalyst temperature.