Check Engine Lights

A question we often hear at our shop is “why is my check engine light flashing?”  There is not always a simple and quick answer to this question.

Check engine lights are a part of the computerized engine management system (ECM).  This system alerts us to possible problems inside the engine or transmission that have an impact on the emissions system.  Check engine lights may be a graphic of an engine or a similar icon.  It could also be words “check engine” or “service engine”.  Some vehicles use a yellow check engine light as a caution light that tells you to have your car checked soon and a red check engine light that means your vehicle needs immediate attention.  Every car’s display is different, so you should make yourself familiar with how your particular make and model works.  The check engine light is usually amber or red in color and has two stages, a steady engine light or a flashing check engine light.  A steady check engine light signals minor problems, while a flashing check engine light means there is a serious problem in the ECM.

The specific causes a check engine light flashes are different for each vehicle but these are some general causes.

• A misfire in your engine.  A misfire can cause catalytic converter damage if you don’t resolve it quickly.  Replacing a catalytic  converter can be costly, so have the engine checked as soon as possible by a certified mechanic.
• A failure in the emission control system.  The emission control system contains many active sensors that work to reduce the amount of pollution released into the air.  One of those sensors is an oxygen sensor that reads the air and fuel mixture.  If that mixture is out of the acceptable range the check engine light will flash.
• Brittle, cracked or worn spark plugs.  Worn spark plug wires can lead to an electric misfire inside the engine.  If the wires are worn out, they should be changed as soon as possible.
• A loose gas cap.  If the gas cap isn’t tight enough or twisted correctly it can cause the check engine light to flash.  Sometimes when the cap is put on correctly the check engine light will go off.  If the light stays on for more than a day or two have your mechanic run an on-board diagnostic to see if there is a code in the system indicating a more serious problem.

Check engine lights help you and your mechanic keep your vehicle running smoothly, so when they light up have your vehicle checked and don’t ignore them!

For all of your Denver Auto Repair needs, trust Express Car Care. Call (303) 691-2760 or stop by our shop today.