When Your Check Engine Light Comes On

A steady check-engine light usually means the vehicle computer detected a fault that should be diagnosed. A flashing light can indicate an active misfire that may damage the catalytic converter.

Do not diagnose from the code alone

A trouble code points to a system or condition, not automatically to one failed part. Accurate diagnosis may require testing wiring, sensors, fuel delivery, mechanical condition, and service information.

If the light flashes, the engine runs badly, or other warning lights appear, reduce risk and ask a qualified shop whether the vehicle should be driven.