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P0102

Mass Air Flow Sensor Circuit Low Input

The engine computer is getting a weak signal from the mass air flow sensor. This usually happens when the sensor is unplugged, the wiring or connector is damaged, or the sensor has failed.

Severity3/5 Moderate
Can I drive?⚠ With caution

You can usually drive short distances, but the engine may run poorly, stall, or have reduced power. Fix it soon to avoid drivability problems and possible fuel economy issues.

DIY
$0–$180
Shop
$100–$350
Difficulty
easy

What It Means

P0102 means the powertrain control module has detected a mass air flow sensor signal voltage or frequency that is lower than the expected operating range. The MAF sensor measures incoming air so the PCM can calculate fuel delivery. When the signal is too low, the PCM may switch to backup values and turn on the check engine light.

Symptoms

Common Causes

1. MAF sensor unpluggedhigh
2. Damaged MAF wiring or loose, corroded connector terminalshigh
3. Faulty mass air flow sensorhigh
4. Poor power or ground supply to the MAF sensormedium
5. Air intake duct problem causing incorrect airflow measurementmedium
6. PCM issuelow

Related Codes

FAQ

Can a dirty or unplugged MAF sensor cause P0102?

Yes. An unplugged sensor is a very common cause, and a sensor with electrical problems can also trigger a low input code.

Will P0102 cause rough running?

Yes. The engine may idle roughly, hesitate, stall, or feel weak because fuel delivery is based on incorrect airflow information.

Should I replace the MAF sensor right away?

Not before checking the connector and wiring. A loose plug, damaged wires, or corroded terminals are common and can cause the same code.