P0102

Mass or Volume Air Flow Sensor A Circuit Low

Fuel & air metering Generic OBD-II High

What it means

P0102 means the mass air flow (MAF) sensor is sending a lower-than-expected signal to the engine computer. With a bad airflow reading the ECM can't meter fuel correctly, so the engine may idle roughly, hesitate, lose power and use more fuel. The car will usually still run, but drivability suffers until it's fixed.

High

Can I keep driving? Usually driveable but the engine runs rough and down on power; prolonged lean/rich running strains it, so fix it soon.

Real-world scan data

Seen in

6,849

scans in the past year

Found in

1.1%

of scans

Appears alongside · share of P0102 scans

P0113in 60.6% of scans

P0101in 12.3% of scans

P0100in 6.4% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Rough or unstable idle
Hesitation and reduced power on acceleration
Increased fuel consumption

Common causes

Most likely first

Dirty or contaminated MAF sensing elementLikely
Unmetered air leak between the MAF and throttle bodyCommon
Loose or corroded MAF connectorCommon
Damaged wiring in the sensor circuitLess often
Failed MAF sensor (ECM failure is rare)Less often

How to diagnose & fix

Work through it in order

Inspect and clean the MAF element with dedicated MAF cleaner — never touch it by hand.
Check the intake ducting, clamps and boot for cracks or air leaks after the MAF.
Inspect the MAF connector and wiring for corrosion, looseness or damage.
Compare live airflow readings to a known-good value; replace the MAF if it still reads low.
Only consider the ECM after sensor, wiring and intake checks pass.

P0102 by make

Based on commonly reported failure patterns across owner and repair communities, not on our scan data.

BMW

BMW's hot-film MAF sensors are a known wear item, and a failing one often shows up as this code along with rough running. Cracked intake boots are worth checking at the same time.

Chevrolet

On Chevrolet trucks and cars this is commonly a dirty MAF sensor, sometimes from an oiled aftermarket air filter. Check the connector and cleaning the sensor before buying a new one.

Ford

Often traced on Ford trucks and SUVs to a dirty or failing mass airflow sensor, or a loose or corroded sensor connector. Cleaning it with a spray made for MAF sensors is a cheap first step.

Nissan

Commonly reported on Nissans such as the Altima, Sentra and Frontier from a dirty or aging MAF sensor. Cleaning it or checking its connector is the usual first step.

Toyota

On Toyotas the MAF sensor is often simply dirty, particularly if an aftermarket or oiled air filter has been fitted. Cleaning it with MAF-specific spray often clears the code before a replacement is needed.

Volkswagen

On VW and Audi models a failing MAF sensor or a damaged connector at the sensor is a commonly reported cause. Check the intake hoses for splits as well, since they affect airflow readings.

FAQ

Quick answers

Is it safe to drive with P0102?+

Short-term yes, but the engine will run rough and lose power. Because the ECM is metering fuel from a bad airflow signal, don't put it off — extended lean or rich running can foul plugs and stress the catalytic converter.

Can I just clear P0102?+

It will return within a drive cycle or two unless the MAF, its wiring or an intake leak is actually fixed.