P0102 on a BMW: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

You can usually drive a BMW with P0102, but the engine may run rough or use more fuel until the sensor is fixed.

What P0102 means on a BMW

On a BMW, P0102 means the hot-film air mass meter is sending a signal that is too low. BMWs combine the MAF and intake air temperature sensors in one air mass meter, so a low signal usually points to that part. Oil and dirt from the engine's crankcase ventilation coat the sensing element over time.

Is P0102 common on BMWs?

P0102 is common on BMWs with higher mileage, especially 3 Series, 5 Series, X3, and X5 models. The air mass meter gets contaminated by oil vapor from the crankcase ventilation system, which makes its signal drop. Cleaning the element can help, but replacement is often needed.

Commonly reported on: 3 Series, 5 Series, X3, X5.

Symptoms

Check engine light on
Rough idle or hesitation
Stalling at stops
Worse fuel economy

Common causes

most common: Contaminated hot-film air mass meter
common: Faulty air mass meter
common: Oil contamination from crankcase ventilation
less common: Wiring or connector problem

How to fix it

Fix	DIY?	Typical cost
Clean the air mass meter with MAF cleaner	Yes	$10–15
Replace the air mass meter	Yes	$150–350
Repair the crankcase ventilation system	Mechanic	$150–400
Repair the wiring or connector	Mechanic	$80–200

Frequently asked questions

Can I drive my BMW with a P0102 code?

Yes, usually. The engine may run rough or use more fuel, but it is safe for short drives while you fix it.

Why does this happen on BMWs?

BMW air mass meters sit in the intake where oil vapor from the crankcase ventilation coats the sensing element. That contamination makes the signal drop over time.

How much does it cost to fix P0102 on a BMW?

Cleaning costs about $10 to $15. A replacement air mass meter runs $150 to $350, and it is a straightforward DIY swap on most BMWs.