Check Engine Light Flashing? What It Means and What to Do

What Does a Flashing Check Engine Light Mean?

A steady check engine light means the computer has logged a fault. A flashing light usually signals an active misfire, which can overheat and damage the catalytic converter. We say usually because many different faults share this one light, and only a scan can tell you which one you have.

Is It Safe to Keep Driving With a Flashing Check Engine Light?

Reduce speed, avoid hard acceleration and have the car checked right away. If the car runs rough, loses power or overheats, have it checked immediately instead of waiting for a convenient day. Ignoring it can turn a small repair into an expensive one.

Why Does It Flash When the Engine Shakes?

A rough, shaking engine often goes with a misfire, and a misfire is what a flashing light usually reports. Worn spark plugs and ignition coils are among the frequent causes, but they are not the only ones. Because so many different faults share one light, guessing is unreliable.

What If the Light Flashes and Then Stops?

Have it scanned anyway. Even when the light has stopped flashing, the car has stored a code that a technician can read. A quiet light is not proof that the fault is gone.

What Does a Diagnostic Scan Show?

A scan reads the stored trouble codes. A code points to a system, not always to a single part, so a technician uses the codes along with live data and testing to confirm the actual cause. That way you replace what is broken instead of guessing.

Frequently Asked Questions

• Can I drive with a flashing check engine light? Reduce speed, avoid hard acceleration and have it checked right away. If the vehicle runs rough, loses power or overheats, have it checked immediately.
• Why is my check engine light flashing and the engine shaking? A flashing light usually signals an active misfire, and a misfire often makes the engine run rough. A scan and testing are needed to find the cause.
• Will the flashing stop on its own? It may, but the car has still stored a code that a technician can read. Have it scanned.
• Steady or flashing: what is the difference? A steady light means a fault was logged and should be diagnosed soon. A flashing light usually points to an active misfire and is more urgent.
• Do you diagnose check engine lights? Yes. We offer engine diagnostics at our shop in Glenn Dale, MD. Call (240) 260-3955 to talk through what you are seeing.