P0102 Mass air flow (MAF) sensor A circuit low
What P0102 means
The mass air flow sensor measures how much air enters the engine so the computer can add the right amount of fuel. P0102 means its signal is below the plausible range. The computer then falls back on estimated values, so the engine may run poorly and have reduced power.
P0102 is a generic SAE J2012 code: it means the same on every make. The exact cause still depends on the car, so read the freeze-frame data before replacing parts.
At a glance
- Severity
- High
- Typical repair cost
- 40–350 €
- Workshop time
- 0.3–1.5 h
- Repair difficulty
- Easy
- DIY possible
- Yes
- Check engine light
- Yes
- Affects emissions test
- Yes
Parts and labour at an independent workshop in Europe. Main dealers charge more; the cause decides the bill, not the code.
Symptoms
- Check engine light on
- Hesitation, poor acceleration or reduced power
- Rough idle or stalling
- Hard starting
- Black smoke on some diesels
Common causes
- Dirty or contaminated MAF sensor element
- Failed MAF sensor
- Unplugged connector, broken wire or poor ground
- Air leak between the MAF and the throttle (split intake hose)
- Very dirty air filter restricting air flow
Can I keep driving with P0102?
Have it looked at within a few days. The engine runs on a substitute value, which can cause hesitation in traffic and higher fuel consumption.
What to check first
- Check the air filter and the MAF connector; make sure it is fully seated and free of corrosion
- Inspect the intake hose between the MAF and throttle for cracks or loose clamps
- Clean the sensor element with dedicated MAF cleaner (never touch the element)
- Check live MAF readings at idle and full throttle; replace the sensor if values remain low
Related codes
- P0101 Mass air flow sensor A range/performance
- P0103 Mass air flow sensor A circuit high
- P0100 Mass air flow sensor A circuit
- P0104 Mass air flow sensor A circuit intermittent
- P0105 Manifold absolute pressure / barometric pressure sensor circuit
- P0106 Manifold absolute pressure / barometric pressure sensor range/performance
- P0107 Manifold absolute pressure / barometric pressure sensor circuit low
- P0108 Manifold absolute pressure / barometric pressure sensor circuit high
Data: TORKO fault-code catalogue, built on OBDex (CC0-1.0) and reviewed against workshop practice. Informational only — it does not replace a diagnosis by a mechanic.
Updated: