P0101 on a Mercedes-Benz: Causes, Fixes & Repair Cost

🟠 Moderate severity · drivable

You can usually keep driving a Mercedes with P0101, but a bad MAF reading can cause rough running and reduced performance until it's fixed.

What P0101 means on a Mercedes-Benz

On a Mercedes-Benz, P0101 means the mass air flow sensor is reporting an airflow reading outside the expected range. Mercedes uses the MAF reading to manage fuel delivery, and a bad reading can cause rough running, hesitation, and reduced performance.

Is P0101 common on Mercedes-Benzs?

P0101 is seen on Mercedes models like the C-Class, E-Class, and GLK. The hot-film MAF sensor can fail with age, and intake leaks or a dirty element are common triggers.

Commonly reported on: C-Class, E-Class, GLK, ML-Class.

Symptoms

Check engine light on
Rough idle
Hesitation when accelerating
Reduced performance or worse fuel economy

Common causes

most common: Faulty or contaminated MAF sensor
common: Intake or vacuum leak
common: Dirty MAF element
less common: Damaged wiring or connector
less common: Dirty air filter

How to fix it

Fix	DIY?	Typical cost
Clean the MAF sensor with sensor-safe cleaner	Yes	$10–20
Inspect the intake and vacuum lines for leaks	Yes	$0–50
Replace the MAF sensor if cleaning doesn't help	Yes	$250–600
Replace the air filter if it is dirty	Yes	$20–60