The check engine light (CEL) is one of the most misunderstood warnings in modern vehicles. It illuminates whenever your vehicle's ECU detects a fault it can't resolve on its own. It doesn't always mean disaster.
Three things the light can mean
- Steady amber light — A fault has been logged. Drive normally but schedule a diagnostic within a few days.
- Flashing light — Active engine misfire. Pull over now. Do not drive at highway speeds — catalytic converter damage risk.
- Red check engine light — On some vehicles, red signals a more severe fault. Treat like a flashing amber.
What to do first
Check your gas cap. A loose or faulty gas cap is the single most common cause of a check engine light — it triggers an EVAP leak code. Tighten it and see if the light clears over the next few drive cycles.
If the light persists, use MyOBDCode to look up your specific code. Every code comes with urgency rating, likely causes, and repair cost estimates.