Although the check engine light may look scary lit up on the dashboard, there is nothing to fear. A glowing check engine light doesn't mean you have to immediately pull over to the side of the road, but it does mean you should get the car checked out as soon as possible. Do not fear when the check engine light is illuminated, it usually means that the vehicle system, such as the ignition, fuel injection or emission control, is not operating properly.
Some common malfunctions that can cause the check engine light to illuminate include a faulty oxygen sensor, mass air flow sensor, or spark plugs and wires. If the light flashes, the condition is more critical and must be checked immediately to prevent severe damage, which may include catalytic converter damage.
Even if the vehicle appears to be running normally, ignoring the warning light could result in more costly repairs. The light could be alerting you to engine problem that is negatively impacting fuel economy and costing you money.
When scheduling a service, make sure the repair shop that examines your vehicle has professional technicians who are trained and certified in OBDII diagnosis and repair. The technician will connect your vehicle's computer system to a diagnostic scan tool, which will provide trouble codes indicating why the check engine light was activated. While the diagnostic tool is connected, the technician can analyze data streams such as the idle speed, throttle response, engine temperature, fuel system pressure, manifold vacuum, exhaust emission levels and many other key indicators. Once the problem is identified and the repair is made, the car's computer is reset to initiate the computer's release process.