Is your check engine light on? Don't ignore it

(July 23, 2013) BETHESDA, Md. — One of the most vital signals of an improperly functioning vehicle is the check engine light and when illuminated, it alerts the driver to a variety of existing potential problems. Vehicle check-ups during community car care events throughout the country reveal that the check engine light is on in nearly one out of ten vehicles, says the Car Care Council.

"When the check engine light comes on, it means that a vehicle system, such as the ignition, fuel injection or emission control, is not operating properly, even if the vehicle appears to be running normally," said Rich White, executive director, Car Care Council.

"A glowing check engine light doesn't mean you have to immediately pull the car to the side of the road, but it does mean you should get the car checked out as soon as possible. Ignoring the warning light could result in costly repairs. At the very least, the light could alert you to an engine problem that is negatively impacting fuel economy."

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.

When scheduling service, make sure the automotive 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 fixed, the car's computer is reset to initiate the computer's release process. The technician should then advise the customer of the proper course of action, potential warranty coverage, further testing if necessary and recommended repairs.