P0103
Mass or Volume Air Flow Sensor A Circuit High
Fuel & air metering
Generic OBD-II
High
What it means
P0103 means the mass airflow (MAF) sensor's "A" circuit is reporting a signal that's higher than the expected range. The MAF tells the ECM how much air is entering the engine so it can meter fuel correctly, so a false-high reading throws off the air/fuel mix — leading to hesitation, poor economy, and sometimes stalling. It's most often a dirty sensor or a wiring fault rather than a failed ECM.
High
Can I keep driving? Usually drivable, but the engine may hesitate, stall, or lose power — get it fixed soon, especially if it stalls or runs very roughly.
Common symptoms
What you'll notice
- Check-engine light on
- Hesitation, surging, or rough running
- Reduced power and poor acceleration
- Poor fuel economy
- Occasional stalling, especially at idle
Common causes
Most likely first
- Dirty or contaminated mass airflow (MAF) sensorLikely
- MAF signal wiring shorted to voltage or openCommon
- Vacuum or intake leak drawing unmetered airCommon
- Corroded or loose MAF connectorLess often
- Failed ECM/PCM (rare)Less often
How to diagnose & fix
Work through it in order
- Inspect the intake ducting between the MAF and throttle body for cracks, loose clamps, or leaks.
- Check the MAF connector and wiring for damage, corrosion, or a short to power.
- Compare the MAF's live airflow reading to expected values for engine size and RPM.
- Clean the MAF element with MAF-safe cleaner; replace the sensor if it still reads high.
- If wiring and sensor are good, check for unmetered air/vacuum leaks. Clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0103?+
Short-term usually, but a bad MAF signal can cause hesitation and stalling. Avoid long trips until it's fixed, and be cautious if the engine stumbles in traffic.
Can I just clear P0103?+
It returns within a drive cycle or two while the MAF keeps reporting a high signal. Clean or replace the sensor (or fix the wiring/leak) first.
Related codes
Often seen with P0103
Read & clear P0103 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