My Car Check Engine Light Is On

What Does the Check Engine Light Mean?

The check engine light is a warning light that is illuminated when the engine control module (ECM) detects a problem with the engine or emissions system. The ECM is a computer that monitors the engine’s operation and adjusts the fuel mixture, spark timing, and other variables to ensure that the engine is running properly.

When the check engine light is illuminated, it means that the ECM has detected a fault code that indicates a problem with the engine or emissions system. The fault code can be used to diagnose the problem and determine the necessary repairs.

What Should I Do If the Check Engine Light Is On?

If the check engine light is illuminated, you should take the following steps:

1. Check the engine oil level. A low oil level can cause the check engine light to illuminate.
2. Check the coolant level. A low coolant level can also cause the check engine light to illuminate.
3. Inspect the air filter. A dirty air filter can restrict airflow to the engine, which can cause the check engine light to illuminate.
4. Have the vehicle scanned for fault codes. A fault code reader can be used to retrieve the fault codes that are stored in the ECM. These fault codes can be used to diagnose the problem and determine the necessary repairs.

Common Causes of the Check Engine Light

There are many different problems that can cause the check engine light to illuminate. Some of the most common causes include:

• Loose or faulty gas cap. A loose or faulty gas cap can allow fuel vapors to escape, which can cause the check engine light to illuminate.
• Oxygen sensor failure. The oxygen sensor monitors the oxygen content of the exhaust gas. A faulty oxygen sensor can cause the engine to run rich or lean, which can lead to the check engine light being illuminated.
• Spark plug failure. A faulty spark plug can cause the engine to misfire, which can lead to the check engine light being illuminated.
• Catalytic converter failure. The catalytic converter converts harmful exhaust gases into less harmful gases. A faulty catalytic converter can cause the check engine light to illuminate.
• Exhaust gas recirculation (EGR) valve failure. The EGR valve recirculates exhaust gas back into the engine. A faulty EGR valve can cause the engine to run rich or lean, which can lead to the check engine light being illuminated.

How to Fix a Check Engine Light

The best way to fix a check engine light is to have the vehicle diagnosed by a qualified mechanic. The mechanic will be able to retrieve the fault codes that are stored in the ECM and use them to diagnose the problem and determine the necessary repairs.

Some check engine light problems can be fixed by the do-it-yourselfer. For example, a loose or faulty gas cap can be tightened or replaced. A dirty air filter can be replaced. However, most check engine light problems require the expertise of a qualified mechanic.

Conclusion

The check engine light is a warning light that should not be ignored. If the check engine light is illuminated, you should take the vehicle to a qualified mechanic for diagnosis and repair.