Trouble code · Powertrain · Generic (all makes)

P0102 Mass or Volume Air Flow 'A' Circuit Low

The signal from the mass air flow (MAF) sensor – which measures air entering the engine – is lower than it should be.

Safe to drive?
Drive with caution
Get it fixed soon
Scanner you need
Any OBD2 scanner
Even a basic code reader shows it
NHTSA complaints quoting it
9
Vehicle complaints, 2015–2025

Common causes

  • Dirty or failed MAF sensor
  • Unplugged or damaged connector or wiring
  • Air leak or loose intake duct after the sensor
  • Clogged air filter

Symptoms

  • Hesitation
  • Stalling after starting
  • Rough idle
  • Poor fuel economy
  • Black smoke in some cases

Can I drive with it?

Usually drivable, but the engine may run poorly or stall – get it checked soon.

Tip: Check that the intake duct is clamped tight and the connector is fully seated – they're often disturbed during air filter changes.

Which scanner reads it?

Any OBD2 scanner reads it. Live data showing grams-per-second airflow at idle and under load makes a bad MAF easy to spot.

Budget tools like the ANCEL AD310 read it; tools with live data and graphing – like the BlueDriver or OBDLink MX+ – help you find the cause. Not sure which fits you? Try the Find My Scanner quiz.

In the data

Of the vehicle complaints owners filed with NHTSA from 2015 to 2025, 9 quote P0102 – most often from Nissan, Mercury, Toyota owners. Complaints lean toward serious problems, so treat this as a sign of how often the code turns up in real reports, not how often cars get it.

Both sources are compared on the Trends page.

General information to help you understand a code – not a diagnosis. Your car’s service information or a qualified mechanic has the final word. See how we research.