P0100
Mass or Volume Air Flow Sensor A Circuit
Fuel & air metering
Generic OBD-II
High
What it means
P0100 means the engine computer has seen a problem in the mass air flow (MAF) sensor circuit — the sensor that measures how much air is entering the engine. Because the computer uses that reading to set fuel delivery, a bad signal can make the engine hesitate, idle rough, or stall, even though it will usually still run in a limited "limp" mode.
High
Can I keep driving? Usually drivable, but the engine may hesitate, stall, or idle rough — fix it promptly, and don't ignore stalling.
Common symptoms
What you'll notice
- Check-engine light on
- Reduced power and hesitation on acceleration
- Rough idle or stalling
- Poor fuel economy
- Hard starting in some cases
Common causes
Most likely first
- Dirty or contaminated MAF sensor elementLikely
- Faulty mass air flow (MAF) sensorCommon
- Damaged wiring or a loose/corroded MAF connectorCommon
- Vacuum or intake leaks after the MAFLess often
- Clogged air filterLess often
- Failed PCM (rare)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and inspect the MAF connector and wiring.
- Clean the MAF element with dedicated MAF cleaner — a common, cheap fix.
- Check the air filter and intake ducting for splits or leaks after the MAF.
- Compare MAF readings against expected values with a scan tool.
- Replace the MAF sensor if it's faulty; consider the PCM only after everything else checks out.
FAQ
Quick answers
Is it safe to drive with P0100?+
Short trips are usually possible, but if the engine stalls or bogs down it isn't safe. The computer runs on a rough estimate without a good MAF signal, so get it fixed soon.
Can I just clear P0100?+
It will return within a drive cycle or two unless the sensor, wiring, or intake leak is repaired.
Related codes
Often seen with P0100
Read & clear P0100 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX