Common failures that can trigger a "check engine" light include:
* Failed engine-control components such as an oxygen, coolant temperature, MAP (manifold absolute pressure) or airflow sensor.
* Engine misfires from faulty sparkplugs, sparkplug wires, ignition components, fuel injectors or other fuel system parts.
* Emission-control failures such as loose or cracked vacuum hoses, a loose or missing gas cap or a defective EGR (exhaust gas recirculation) valve.
How you should react to a "check engine" light depends on how the light behaves. If the light comes on for a little while and then goes out, you may have had a momentary problem in the system. The light goes out when the problem stops, but the computer could have stored a diagnostic trouble code in its memory. If the light does not recur, it can be ignored. However, if the light comes and goes intermittently, take the vehicle in for a checkup.
If the light comes on and stays on, the car has an ongoing problem. While that problem may not be severe, it will negatively impact your car's performance, gas mileage and exhaust emissions. Take your vehicle to a repair shop as soon as possible for further diagnosis.
If the "check engine" light begins to flash on and off, a severe problem is causing the catalytic converter to overheat. This can destroy the converter and possibly even start a fire. If your repair shop is nearby, drive there immediately. If the shop is some distance away, shut off the car and call for assistance. Always have the cause of a flashing "check engine" light investigated right away to prevent damage to important components that can greatly increase the cost of repairs.
AAA Approved Auto Repair facilities can diagnose "check engine" light problems and provide a full range of vehicle maintenance and repair services. Approved Auto Repair shops meet AAA's high standards for customer care and technical proficiency. To locate a shop near you, look for the AAA Approved Auto Repair logo or visit www.AAA.com/repair.