P0100
MAF Sensor Circuit Malfunction
medium
i Description
The Mass Air Flow (MAF) sensor circuit has a malfunction. The ECU detected an unexpected voltage or signal from the MAF sensor, which measures the volume and density of air entering the engine. This data is critical for calculating the correct fuel injection amount.
? Common Causes
- Dirty or contaminated MAF sensor element
- Damaged MAF sensor wiring or connector
- Air leak between MAF sensor and throttle body
- Faulty MAF sensor
- Rodent damage to wiring
! Symptoms
- Check engine light
- Poor fuel economy
- Rough idle or stalling
- Hesitation on acceleration
- Black smoke from exhaust
# Diagnostic Steps
- Inspect MAF sensor connector for damage or corrosion
- Check for air leaks in the intake duct after the MAF
- Clean the MAF sensor with dedicated MAF cleaner spray
- Test MAF sensor output with a scan tool (compare to specs)
- Check wiring continuity between MAF and ECU
⚙ Typical Fix
Clean or replace the MAF sensor. Inspect and repair any air intake leaks.
Parts Needed
MAF sensor, MAF sensor cleaner
Estimated Cost
$50-$350
↔ Related Codes
Q Frequently Asked Questions
You can drive short distances, but fuel economy and performance will suffer. The engine may run rich or lean, potentially causing catalytic converter damage over time. Get it checked within a week.
Yes — cleaning the MAF sensor is a common DIY fix. Buy a can of MAF sensor cleaner (around $15), remove the sensor, spray the sensing element, let it dry, and reinstall. This resolves the issue about 50% of the time.
If cleaning works, just the cost of MAF cleaner ($15). A new MAF sensor runs $80-$300 depending on the vehicle, plus $50-$100 labour if you take it to a mechanic.
☞ Learn More
- What is OBD-II? — Complete guide to your car's diagnostic system
- How to Read DTC Codes — Step-by-step with a Bluetooth scanner
- OBD-II Scanner Buying Guide — Find the best scanner for your car