Hot-Film Air Mass Meter (HFM), Bosch - E90 335d, E70 X5 35d, M57

This part is listed by BMW as BMW part number 13628509725 (13-62-8-509-725) and is described as the HFM (Hot-Film Air Mass Meter) for E90 335d and E70 X5 35d.

The HFM (Hot Film Meter, or MAF) measures air density and temperature in the intake so the engine computer can make fuel adjustments on the fly. When it goes bad and no longer sends data the ECU will revert to a rich setting (more fuel) and eventually it will throw a fault code. If you're having drivability issues or MPG has dropped, remove the HFM and intake boots, clean with HFM cleaner, check for cracks in the boots, and reinstall. If problems persist it may be time for a new HFM.

This is an OEM M57 HFM manufactured by Bosch - the original supplier to BMW for this part, as well as many other sensors. As the OEM it meets all of BMW's original design, fitment, and performance requirements and is TUV approved. OEM parts are the best alternative to more expensive Original BMW parts because they are virtually identical without the inflated price tag. This part has a two year warranty.

For full BMW fitment information or for assistance from one of our BMW experts, we recommend calling us at 877-639-9648.