If you’re a car owner, you’re probably familiar with the pit you get in your stomach when you see the infamous check engine light turn on. Unfortunately, while we may be tempted to ignore it, that can lead to costly repairs or even a damaged engine down the road. The check engine light is an important part of your vehicle’s onboard diagnostics system. When this light turns on, it means something is not working correctly in your car’s engine or emission control system. Therefore, it’s important for drivers to learn what it means when the check engine light turns on and when to visit a mechanic. 

Key Takeaways

  • Don’t Ignore the Light: Address the check engine light promptly to avoid costly repairs and ensure your vehicle runs efficiently.
  • Common Causes: Your check engine light may be caused by a loose gas cap, faulty oxygen sensor, or issues with the mass airflow sensor.
  • Seek Professional Help: Visit a qualified mechanic to diagnose and fix the issue, especially if the light is flashing, which indicates a severe problem.

Learn what the check engine light means with The General. The next time your check engine light turns on, you’ll be prepared with this advice. Common reasons for the light: loose or faulty gas cap, oxygen sensor issues, mass airflow sensor issues, catalytic converter problems, or spark plug or ignition coil problems. What to do if it comes on? Check the gas cap, get a diagnostic test, look for other warning signs.

What Causes the Check Engine Light to Turn On? 

When the dreaded check engine light turns on, it means that your vehicle’s computer system detected a problem with one or more of the components that make up your car’s engine or emission system. While you may be tempted to start panicking, it’s worth noting that the check engine light can turn on for a variety of reasons, and not all of them are worse-case scenarios. For example, it could be a loose gas cap or a minor issue with your engine that’s easily fixable. However, it’s still important to investigate the problem so you can find a solution. 

Possible Reasons for the Check Engine Light Turning On

There are many possible reasons why your check engine light turns on. Some of the most common reasons include: 

  • Faulty oxygen sensor. Your car’s oxygen sensor measures the amount of oxygen in the exhaust and sends the information to your car’s computer. A faulty oxygen sensor can cause a decrease in fuel economy and an increase in emissions, so your OBD system turns your check engine light on when it detects a problem with it. Think of it as your car’s way of saving you money in the long run!
  • Loose or damaged gas cap. If the gas cap is damaged or doesn’t fit properly, dirt and debris can enter your vehicle, fuel vapors can escape, and the emissions system can report an error to your car’s computer, triggering the check engine light.
  • Malfunctioning mass airflow sensor. The mass airflow sensor measures the amount of air entering the engine and helps determine the correct fuel-to-air ratio. Problems with your mass airflow sensor can decrease fuel economy and increase emissions. Like a faulty oxygen sensor, this can cause your check engine light to turn on.
  • Faulty spark plugs. Spark plugs ignite the air/fuel mixture in the engine, so it’s important that they’re operating in top shape. Faulty spark plugs can cause misfires, reduced power, poor fuel economy, and a visit from the check engine light.
  • Broken catalytic converter. This important piece of machinery reduces harmful emissions by converting them into safer gases. If it breaks, your engine’s performance can take a hit and start emitting dark exhaust smoke with a funny odor. To prevent this, your check engine light will activate on your dashboard if it senses a gas leak or a damaged converter.  

Depicted: Check Engine Light on Car Dashboard. What does the check engine light mean?

Can I Ignore the Check Engine Light? 

Ignoring the check engine light can have negative consequences for your vehicle. Like any mechanical problem, the sooner it’s addressed, the less time it has to snowball into a more expensive problem. Even if the issue seems minor, your vehicle and your wallet will thank you for bringing it to a qualified mechanic if needed. A minor issue could be a symptom of a more significant problem and catching it early can save you a lot of money. 

Additionally, if the check engine light is on, it could cause your car to fail its emissions test, which you need to pass in order to drive legally and register your vehicle in some states.  

What Are the Consequences of Ignoring My Check Engine Light?

Ignoring the check engine light can lead to serious consequences for your vehicle, like costly repairs. For example, a simple fix like a faulty sensor could turn into a damaged catalytic converter, which is much more expensive to repair. It’s best to address the issue promptly to save time, money, and stress in the long run.

Can I Drive with My Check Engine Light On?

While it’s possible to drive with the check engine light on, it’s not advisable. The light is a warning that something isn’t right with your vehicle. If the light is steady, it usually indicates a less urgent issue, but you should still have it checked as soon as possible. However, if the light is flashing, it signals a severe problem, such as a misfire, which can damage the catalytic converter. In this case, stop driving immediately and have your car towed to a repair shop. Driving with the light on can lead to further damage and more expensive repairs.

How to Reset My Check Engine Light

Resetting your check engine light should only be done after addressing the underlying issue. If the problem has been fixed, the light may turn off automatically after a few driving cycles. If it remains on, you can reset it using an OBD-II scanner, which connects to your car’s diagnostic port. Follow the scanner’s instructions to clear the code. However, if the light turns back on after resetting, it indicates that the problem still exists and needs further attention. Always ensure that any necessary repairs are completed before attempting to reset the light.

When to Visit a Repair Shop

If your check engine light turns on, experts recommend taking your car to a qualified mechanic as soon as possible. During the visit, your repair person will check your computer’s OBD system to find and fix the issue that turned the check engine light on. 

Look for a repair shop that specializes in your car’s make and model and has a good reputation for quality work and customer service. If you have roadside assistance, this is a great time to take advantage of it.  

If your check engine light turns on because of a covered incident, you’ll need a quality insurance policy to help cover the cost of repairs. That’s where The General comes in. Check out our affordable rates when you get a car insurance quote in under two minutes or read more on our insurance blog.