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P0101 — Mass Air Flow Circuit Range/Performance

P0101 means: The mass air flow sensor reading is outside the range the controller expects for current engine speed and throttle position.

System: Fuel & Air Metering · Standard: SAE J2012 generic code · Severity: Repair soon

01Can you keep driving?

Repair soon

The car will usually keep running, but continued driving risks secondary damage or an emissions failure. Book the repair.

02What you will notice

03Likely causes, most common first

  1. Dirty or contaminated sensor element
  2. Unmetered air leak between sensor and throttle body
  3. Clogged air filter
  4. Failing sensor

04How this code is diagnosed

This is the most common air-metering code. Cleaning the sensor element and checking for intake leaks resolves most cases.

Start by reading every stored and pending code, not just this one. A single fault frequently sets three or four codes at once, and the first one in the freeze-frame data is usually the cause while the rest are consequences.

Common questions

What does P0101 mean?

The mass air flow sensor reading is outside the range the controller expects for current engine speed and throttle position. Mass Air Flow Circuit Range/Performance is a generic fuel & air metering code defined by SAE J2012, so it carries the same meaning on every OBD-II vehicle.

Is it safe to drive with P0101?

Repair soon. The car will usually keep running, but continued driving risks secondary damage or an emissions failure. Book the repair.

What are the most likely causes of P0101?

In rough order of how often they turn out to be the problem: Dirty or contaminated sensor element; Unmetered air leak between sensor and throttle body; Clogged air filter.

Other fuel & air metering codes

Sourcing

Code number, system and definition follow the SAE J2012 / ISO 15031-6 generic diagnostic trouble code standard. Symptoms, causes and severity are the standard generic diagnostic logic for that fault. This page does not contain manufacturer-specific procedures, part numbers or pricing.