What it means
The check engine light, also called the engine management light, MIL, or malfunction indicator lamp, is triggered when the car's computer sees a problem in the engine, fuel, ignition, or emissions system. The car may still feel normal, but a stored fault code can explain what the system detected.
What to do first
- Check whether the light is steady or flashing.
- Tighten the fuel cap if your car has one, then see whether the light clears after a few trips.
- Avoid hard acceleration, towing, or high-speed driving until the cause is known.
- Scan for diagnostic trouble codes if the light stays on.
Common causes
- Loose or faulty fuel cap
- Oxygen sensor or emissions sensor fault
- Ignition misfire, coil, or spark plug problem
- Mass airflow sensor fault
- Catalytic converter efficiency problem
When to stop driving
If the check engine light is flashing, reduce speed and avoid heavy throttle. A flashing light can mean an active misfire that may damage the catalytic converter. Stop sooner if the car shakes, loses power, overheats, smells like fuel, or shows another red warning light.
Check Engine Light FAQ
Is a steady check engine light safe?
Often yes for a short period if the car drives normally, but the vehicle should still be scanned and repaired soon.
Can a loose fuel cap cause it?
Yes. A loose or damaged fuel cap can trigger an evaporative emissions fault on many petrol/gasoline vehicles.
Related symbols
Dashboard symbols vary by make and model. Always confirm the exact meaning in your owner's manual.