Air Management

Air Management
Hot Film Air Mass Sensor (HFM)





A new hot film air mass sensor (HFM) manufactured by Siemens is used for the M54 in the E60. The HFMis located behind the air filter housing in the intake air ducting.





The HFM is inserted in the air filter housing (plug in) and secured with two screws. In this position the HFM is freely suspended in the intake air flow. The HFM is more compact in design than its predecessor and the grill is now omitted. This compact design decreases pressure loss in the intake track.
Its operation and output signals are the same as the previous HFM. The intake air temperature sensor is integrated in the HFM.