41F2 Electric fan activation

Fault code 41F2 Electric fan activation is related to the problem with electric fan. Electric fan is use to cool down heating of engine coolant system. In BMW electric fan is work on the basis of PWM (Pulse with modulation) signal. In most of vehicle there are two fan’s one is for engine cooling and the other one is for AC. But in bmw there is only one fan, it work for both engine cooling and AC (Air Conditioning) . If fault code 41F2 Electric fan activation is store in engine control module than it means fan is not working.

Causes of 41F2 Electric fan activation :

  • Faulty control module of electric fan.
  • Blown fuse of electric fan.
  • Damage wiring harness of electric fan.
  • Faulty engine coolant temperature sensor.

Symptoms of 41F2 Electric fan activation :

  • Engine cooling fan wil stop working.
  • Over heating problem will occur.
  • AC will not work.
  • Fault code will store in control module.

How to trouble shoot :

  • In BMW when electric fan stop working, mechanic need to scan fault code with the help of scan tool. When found fault code 41F2 Electric fan activation.
  • First check connector of electric fan if it is loose than make it proper connection.
  • If fan connection is proper than start engine and switch on AC, now fan should start running if still fan is not working than place your hand on the motor of fan if it is vibrating slowly than it means that fan motor is stuck. Try to make it free so that it can work properly. But in case you did not feel any vibration at fan motor than it means fan is completely not working.
  • There might be two reason behind electric fan not completely working. One is either fan is completely dead and the other one is fan is not getting proper signal.
  • In BMW electric fan work on the basis of PWM ( pulse with modulation )signal. There are three wire’s at the connector of electric fan. 1) 12+v, 2) ground and the 3) PWM ( pulse with modulation )signal wire. Both positive and negative current are always there at electric fan connector. For working of electric fan PWM signal is require from control module. We cannot check PWM ( pulse with modulation ) signal with multimeter. If you want to check PWM signal you need other device which is capable of reading PWM signal. So that you can rectify that if there is any problem with PWM signal or not.
  • If power supply, ground and PWM signal is good but still fan is not working.
  • Than the other thing in this case is faulty coolant temperature sensor. engine coolant temperature sensor send signal about temperature of engine coolant , according to which engine control module turn ON and OFF electric fan as per the requirement. Faulty engine coolant temperature sensor send wrong signal to engine control module due which either electric fan turn ON at high speed or it will not turn ON.

Solution :

  • Replace faulty electric fan.
  • Repair damage ground wire.
  • Replace faulty control module.
  • Replace blown fuse.
socket of BMW electric fan

Special note :

When Fan is not working than all the possibility that could be happen are given above. Before replacing electric fan check all these thing if all the other things are good than only replace electric fan.

Due to faulty engine coolant temperature sensor fan could run at high speed at engine start. Some time fault of engine coolant will not store in engine control module. To check engine coolant temperature read data stream. There you will come to know that coolant temperature sensor is working or not. If temperature sensor is woking than reading of it should increase slowly when engine is start. If its reading is now moving or moving too fast while engine is running continuously than it means its is not working.

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