OBD-II fault code

P0102: Mass Air Flow Circuit Low Input

Safe to drive?

Drive with care — fix it soon

Drivable in fallback mode for short necessary trips; expect poor manners. Diagnosis is usually fast because electrical faults measure cleanly.

P0102: Mass Air Flow Circuit Low Input — illustration

What P0102 means

Where P0101 means the MAF's story doesn't add up, P0102 means the signal itself is electrically too low — near zero volts — as if almost no air is entering a running engine. That's an electrical fact, and it points at the sensor or its wiring rather than airflow itself.

What you’ll notice

  • Check engine light
  • Stalling or very rough running, especially at idle
  • Hard starting
  • Engine may run in a noticeable limp mode

Likely causes and repair cost

Broad US independent-shop bands, parts and labour.

Unplugged, corroded, or damaged MAF connector and wiring
$0–$150
Failed MAF sensor
$150–$400
Blown fuse or wiring fault on the sensor's supply
$10–$200

Can you drive with P0102?

Drivable in fallback mode for short necessary trips; expect poor manners. Diagnosis is usually fast because electrical faults measure cleanly.

The misdiagnosis to avoid

Where the money goes wrong

Skipping the connector. A P0102 after other engine work is very often a connector left loose or a wire pinched — sensors get condemned for a plug that wasn't clicked home. Unplug, inspect pins, reseat firmly, clear the code, and only then talk parts.

Not sure this matches your car?

Describe what it’s doing in your own words and the symptom checker gives you a safe-to-drive verdict, ranked causes with costs, and notes to take to the shop — free, no sign-up.

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Read the code yourself

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Diagnostics~$25

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OBDLink MX+ Bluetooth OBD2 Adapter

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Questions people ask

The code came back right after I cleared it — what does that tell me?

With circuit-low codes, an instant return means the fault is present constantly — a dead sensor or broken wire — while a return after days points at intermittent connection trouble. Instant returns are actually the easy case: whatever is wrong is wrong right now and can be measured.

Can I drive with the MAF unplugged as a test?

On many engines, yes, briefly — unplugged, the computer switches to fallback fuelling, and if the engine runs better unplugged than plugged in, the sensor is feeding it worse-than-nothing data. It's a legitimate quick test; just don't make a lifestyle of limp mode.