What to Do When Your Check Engine Light Comes On

Key Takeaways

  • Understanding why the check engine light comes on and its implications.
  • Immediate steps to take when your check engine light flashes.
  • Importance of professional diagnostics to uncover the root issue.
  • How to prevent future occurrences of the check engine light turning on.
  • The role of regular maintenance in keeping your vehicle in optimal condition.

When you’re behind the wheel, your car’s dashboard is the primary point of communication between you and your vehicle. All the more reason to pay attention to it at all times, especially if the check engine light comes on. 

The check engine light (CEL) is one you can’t ignore among the various signals and icons. It’s not just a trivial indicator; it’s your car’s cry for help that something is wrong. In this guide, we’ll be walking you through the possible problems your CEL may be telling you. 

For any car maintenance-related queries, feel free to contact our experts at Auffenberg Chrysler of Herrin. Come in today, and let’s take care of your vehicle.

Why Does the Check Engine Light Come On?

The Check Engine Light can illuminate for various reasons ranging from trivial issues to severe problems that require immediate attention. This light is connected to your car’s onboard diagnostic system, which monitors the engine’s operation. 

Any irregularity this system detects results in the check engine light turning on. Common reasons for the check engine light include:

  • Faulty oxygen sensors.
  • Loose gas caps.
  • A failing catalytic converter.
  • Bad spark plugs.
  • A malfunctioning mass airflow sensor. 

Remember, some of these issues can lead to significant damage if not addressed promptly.

Immediate Steps to Take

Don’t panic when you see the check engine light come on. Instead, follow these steps:

  • Check for Serious Issues: Inspect for signs of serious issues, such as steam from the hood, irregular engine noises, or a noticeable reduction in performance. If you notice these signs, safely pull over and call for roadside assistance.
  • Tighten Your Gas Cap: An improperly secured gas cap can cause the CEL to light up. If your gas cap is loose, tightening it may solve the problem. After a few drives, if the light remains on, the issue could be something else.
  • Reduce Your Speed and Load: If there are no visible signs of a severe issue, reduce your speed and avoid heavy acceleration to decrease the strain on the engine until you can have the vehicle inspected.

Importance of Professional Diagnostics

While these steps can help you navigate the initial phase of a check engine light situation, getting professional diagnostics is crucial. Only a trained mechanic with the right tools can accurately diagnose the underlying issue causing the light to come on. 

Professional diagnostics ensure the root cause is addressed, preventing future occurrences and engine damage.

Remember that ignoring a flashing check engine light can result in significant repair costs. Hence, a timely visit to the mechanic can save you from potential headaches and expenses.

Preventing Future Occurrences of the Check Engine Light

Prevention is often the best cure. Regular maintenance prevents your check engine light from turning on unexpectedly. 

Here are some proactive measures you can take:

  • Regular Servicing: Ensure your vehicle is serviced according to the manufacturer’s schedule. Standard service includes checks and replacements of components that, if faulty, can trigger the CEL.
  • Prompt Repairs: Never postpone minor repairs, as they could lead to significant problems, causing the Check Engine Light to illuminate.
  • Fuel Quality: Always use high-quality fuel and the type recommended in your vehicle’s owner’s manual. Poor-quality fuel can lead to engine problems, often indicated by a flashing CEL.
  • Professional Inspection: Have your car inspected by professionals regularly. They can detect and resolve issues before they become serious.

Understanding the Role of Maintenance

Maintenance goes beyond ensuring the smooth running of your vehicle. It also extends the life of your car and saves you from costly repairs. 

Keep your vehicle’s maintenance schedule on track by paying attention to your car’s needs and addressing issues as soon as they surface. This attention to detail will ensure your check engine light stays off and your vehicle stays on the road longer.

The Impact of Ignoring Your Check Engine Light

Often, drivers are tempted to ignore the check engine light, especially when the car seems to be running just fine. But doing so can have far-reaching consequences. Ignoring the CEL could mean exacerbating a minor issue that could have been resolved quickly, ultimately resulting in costly and extensive repairs.

Also, unaddressed engine issues can lead to decreased fuel efficiency, increased emissions, and even a potential breakdown. Your vehicle might also fail an emissions test if the problem causing the check engine light is not resolved. 

In some cases, it could also lead to irreversible engine damage. That’s why you should always pay attention to a lit check engine light, no matter how well the car operates.

The Power of Advanced Diagnostics

With the advancement of automotive technology, car diagnostics have become more sophisticated. Modern diagnostic tools can precisely identify the issue triggering the check engine light, saving you time and money on unnecessary repairs. 

These tools connect to the vehicle’s onboard computer system to read and interpret the error codes, providing the technician with valuable data about the car’s condition.

Apart from the initial diagnostic process, these tools can also monitor real-time data to assess other potential issues that might not be immediately apparent. 

By leveraging these advanced diagnostic tools, professional technicians can accurately and promptly resolve the problems, ensuring your check engine light turns off and stays off.


Now that you understand the importance of the check engine light and the steps to take when it comes on, it’s time to act. If your check engine light has been flashing, don’t ignore it. Ensure your vehicle gets the attention it deserves by seeking professional help.

Remember, when the check engine light comes on, it’s not just about addressing the immediate issue but also about taking preventative steps to avoid future problems. Regular maintenance is necessary, not an option, to keep your vehicle in optimal condition.
Your vehicle’s health is our top priority at Auffenberg Chrysler of Herrin. Visit us today and let us handle your check engine light concerns.