I have noticed since last week that my 2009 R56 JCW low speed fan doesn't turn on only the high speed fan coming on all the time. With AC turning on, the high speed fan turn on more frequently. Is this normal or me being paranoid.

There isn't any error code popping up at all.

Any help is welcome. Thanks.

 

When this happened to my R56S, it was due to a bad temperature sensor. It acted as if it thought the engine was hot all the time, even when started cold.

 

I managed to find an old temperature sensor from my last thermostat replacement, and replaced with the current one, immediately warming up the low fan speed coming back.

Many thanks for the tips, to replace the temperature sensor. I will get a new one soon.