Flashing vs steady
A steady check engine light means a fault was stored and the car should be inspected soon. A flashing light means the fault may be active right now, often a misfire under load.
What to do first
- Reduce speed and avoid hard acceleration.
- Do not tow heavy loads if you can avoid it.
- Check for shaking, loss of power, or fuel smell.
- Scan for diagnostic trouble codes as soon as possible.
When to stop driving
Stop safely if the car shakes badly, overheats, loses power, or shows another red warning. Continuing to drive with a severe misfire can overheat the catalytic converter.
Common causes of flashing
- Ignition coil or spark plug failure
- Fuel injector problem
- Vacuum leak affecting one cylinder
- Low fuel quality or contaminated fuel
Related symbol guides
More scenarios
This scenario guide is general information only. Confirm warnings with your owner's manual. Read full disclaimer.