Why Is the Check Engine Light On and When Should You Visit a Service?

The check engine light indicates that an engine management or emissions value is outside its expected range. The light alone does not identify the failed part.

Common causes

• Ignition coils or spark plugs
• Air flow and oxygen sensors
• Fuel mixture or injector faults
• Intake air leaks
• Emission system issues
• Low battery voltage

Does a fault code mean a part must be replaced?

No. Wiring, air leaks and related systems can produce the same code. Live data, measurements and physical checks are required for an accurate diagnosis.