What does your check engine light mean?
The check engine light means your car's internal computer has identified a problem with the engine or transmission. A check engine light turning on can mean something minor like a loose gas cap or something more serious like a faulty catalytic converter. It could even be a sign of internal engine failure. Ignoring the problem can turn a potentially quick fix into a costly and time-consuming repair.
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Why is my check engine light on?
Your check engine light might turn on due to one of these common minor or major issues:
- Loose gas cap
- Internal problem in the engine
- An issue with or even theft of the catalytic converter
- Faulty spark plug, spark plug wires, or ignition coils
- Malfunctioning oxygen sensor
- Damaged mass airflow sensor
- A bad tank of gas
A check engine light can mean many different things, so it can be difficult to narrow down your car's issue without a diagnostic code scanner or professional mechanic.
What to do when your check engine light comes on
Once you notice your check engine light has come on, pay attention to how the car is driving. Does something feel off? If so, reroute yourself to a nearby mechanic to get the car checked out. If the car seems to be running fine, consider checking a few things on your own before heading to the mechanic.
Did you just get gas?
A loose gas cap is one of the most common reasons for the check engine light. Check that your gas cap is tightened securely and that it's in good condition.
If you have a tank of bad gas in the car, your check engine light may come on. For example, if your vehicle is designed to run on premium gas (octane grade 91 to 94), the engine may struggle to run on regular gas (octane level 87). You can safely solve this problem by having a professional drain your gas tank. However, if you must drive for a while, the lower grade gas may not cause severe damage, as long as your car doesn't show signs of overheating or poor engine performance.
Get a diagnostic code reading
Do you suspect something else caused your check engine light to turn on? The most foolproof method to check the engine light is to read the diagnostic code in the car's internal computer. If you have experience working with cars, you can do this at home with an OBD-II scanner. Otherwise, head to your local service station, where a mechanic can read the diagnostic code and determine the correct fix.
Can you drive with your check engine light on?
The check engine light generally means you should get your car diagnosed and fixed sooner rather than later. It's best not to drive far with your check engine light, especially if you haven't identified the issue.
The check engine light is sometimes confused with the maintenance required light, but the two are unrelated. The maintenance required light goes on when your car is due for routine service like an oil change. The check engine light is an indication that something unexpected has occurred.
Some later car models have check engine lights in different colors and modes to help you determine how severe the issue is. If your car has this feature, and your check engine light flashes on and off intermittently or glows red, it's a sign you should get your car to a mechanic as soon as possible. Depending on your car's make and model, a solid yellow or orange light may indicate lower severity. However, it's still a sign that you should make an appointment to diagnose and fix the problem.
What happens if I ignore my check engine light?
Ignoring the light and putting off a visit to the mechanic could result in more costly and time-consuming issues in the future. The problem that caused your check engine light to turn on in the first place may get worse or impact other aspects of your car's engine or transmission. Ignoring the problem could lead to more long-term damage that your car insurance may not cover.
You also may not be able to pass your next car inspection until the check engine light is off and you've resolved the problem. Your best option is to get the issue resolved quickly. If you're concerned about affording unexpected engine repairs on your car, consider mechanical breakdown insurance or a vehicle protection plan, which may cover major system breakdowns not covered by your warranty.
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