Check Engine Light Flashing: What Does A Flashing Engine Light Mean?

Imagine driving home after a long day, and then a flashing Check Engine Light suddenly captures your attention. The immediate surge of panic you feel is entirely justified; this warning sign is your vehicle’s way of communicating a critical issue with a component of your engine that requires urgent attention. 

In this article, I will explain the underlying causes of a flashing Check Engine Light and provide a comprehensive guide on the imperative steps to take when your check engine light starts flashing.

check engine light flashing on a car dashboard

Understanding Check Engine Light Indicators

When you notice a Check Engine Light illuminated on your dashboard, it’s crucial to understand that not all warnings are created equal. A static or steady light and a flashing light serve different functions and convey varying levels of urgency.

A static Check Engine Light generally signifies that your vehicle’s engine is experiencing an issue, albeit one that is not immediately critical. 

For example, this could indicate a failing oxygen sensor or a loose gas cap. While such problems still require attention, they are not typically urgent and can often wait until your next service appointment.

Contrastingly, a flashing Check Engine Light elevates the sense of urgency considerably. This is your vehicle’s way of signaling that there is a severe issue, often related to the engine misfiring. But of course, this is different from when you have your check engine light flashing when key is on position.

The ramifications of a flashing check engine light when the car is fully turned on can be very serious, and can potentially cause irreversible damage to expensive components like the catalytic converter.

Other severe engine problems that could prompt a flashing light include abnormal fuel-to-air ratios or problems with the ignition system.

Common Reasons for a Flashing Check Engine Light

1. Engine Misfire

One of the reasons why your car can be flashing a check engine light is an engine misfire. This engine misfire occurs when one or more of your engine’s cylinders fail to fire correctly.

This can happen for a variety of reasons, such as faulty spark plugs, a malfunctioning fuel injector, or problems with the ignition coil.

Engine misfires disrupt the balance and efficiency of your engine. This leads to poorer performance and reduced fuel efficiency and can also place undue stress on crucial components like the catalytic converter, which can be expensive to replace.

You may notice your vehicle stuttering, experiencing reduced acceleration or even stalling. Over time, this could lead to increased emissions and a higher risk of accidents due to impaired functionality.

2. Cracked Cylinders or Severe Oil Leaks

These are issues that can lead to complete engine failure if not addressed promptly. Not only could you be looking at a substantial repair bill, but ignoring these signs could also leave you stranded on the side of the road.

Issues like these can drastically decrease your vehicle’s performance. You may experience poor acceleration, overheating, or your car is not responsive. This could lead to hazardous driving conditions, putting you and other road users at risk.

3. Emission Control System Failure

Your vehicle has several systems in place to control and reduce harmful emissions. When these systems malfunction, your car’s computer will trigger a flashing Check Engine Light.

An Emission control system failure can result in increased pollutants being released into the atmosphere, which is bad for the environment and can lead to legal issues like failing an emissions test.

A malfunctioning emissions system often comes with reduced engine efficiency, leading to performance issues like stalling or difficulty starting the car. This can create unsafe situations, particularly in heavy traffic conditions.

Immediate Steps to Take When the Check Engine Light is Flashing

1. Stop and Park Safely

Identify a safe location to pull over. If it’s not such a busy road, I strongly recommend that you park by the side of the road. Preferably, a spot that’s well-lit if it’s nighttime and provides sufficient space for you to inspect your vehicle safely.

Engage your vehicle’s hazard lights and apply the parking brake. Taking these steps would help to ensure both your safety and that of other road users while you assess the situation.

You also need to take a closer look at your dashboard to see if there are any other warning lights illuminated. You may find yourself in a situation where you have your check engine light flashing and traction control light on. This is a more severe case and I strongly suggest that you don’t drive too far until you have it properly checked out.

2. Observe Symptoms

Take note of any unusual noises, smells, or vibrations. Does the engine sound rough? Is there a smell of burning oil or rubber?

Write down your observations or make a mental note. These could be valuable clues for diagnosing the problem later, either by you or a professional mechanic.

3. Consult the Owner’s Manual

Locate the section in your owner’s manual that deals with the Check Engine Light and troubleshooting.

Follow any preliminary diagnostic steps or guidelines mentioned. The manual often provides essential first-aid measures for various scenarios, including a flashing Check Engine Light.

4. Get Your Check Engine Light Codes Checked

Once safe, you may use an On-Board Diagnostics (OBD) scanner if you have one. This tool will provide error codes that offer insights into what’s wrong with your vehicle.

Plug the OBD scanner into your car’s OBD port, usually located under the dashboard near the steering wheel. Follow the device’s instructions to obtain the error codes and make note of them for further diagnosis.

It’s important to note that there may be situations when you’d have your check engine light flashing but no codes will be displayed on your diagnostics tool. You need to be mindful of that.

5. Reset the Check Engine Light

Some OBD scanners have the capability to reset the Check Engine Light. However, be aware that doing so without addressing the underlying issue is not advisable.

Only reset the Check Engine Light if you’ve identified and rectified the problem causing it to flash. Failure to fix the issue could result in engine failure.

6. Call for Assistance

Determine whether the situation requires professional help. If you are not confident in your ability to identify or fix the issue, it’s best to call for assistance.

Contact a roadside assistance service or a trusted mechanic for immediate support. Brief them on the situation and any symptoms you’ve observed.

Prevention and Maintenance

1. Regular Check-ups

Consistent maintenance appointments with a trusted mechanic would help you detect and resolve symptoms that could eventually lead to a flashing check engine light early. Oil changes, fluid top-offs, and system diagnostics can go a long way in maintaining the engine’s optimal functioning.

Keeping all components in check reduces the likelihood of engine misfires or severe engine problems that could lead to a flashing Check Engine Light.

2. Quality Fuel

Not all fuels are created equal, and opting for a higher-quality fuel can improve engine performance and longevity. High-quality fuels often contain detergents and other additives that clean and protect the engine.

Cleaner engine components are less prone to malfunction, reducing the risk of issues triggering a flashing Check Engine Light, such as misfires or emissions control problems.

3. Addressing Early Any Issue 

The moment you notice something off about your vehicle, be it unusual noises, decreased performance, or warning lights, it’s crucial to address it immediately. Procrastination can turn a small issue into a severe problem.

Quick and timely intervention can prevent the escalation of minor issues into major problems that could result in a flashing Check Engine Light. The sooner you deal with anomalies, the less likely they are to culminate in severe engine damage.


Can I Drive My Car With the Check Engine Light Blinking?

No, driving with a flashing Check Engine Light is highly discouraged. This warning light is an urgent alert indicating that there’s a severe problem with your vehicle, such as a misfire, which could cause damage to the catalytic converter or other critical components.

Continuing to drive under these conditions can lead to costly repairs and may compromise your safety.

Does a Flashing Check Engine Light Mean Transmission Trouble?

A flashing Check Engine Light doesn’t specifically indicate transmission trouble; it’s more commonly associated with severe engine problems like misfires or emission control issues.

However, it’s worth noting that modern vehicles have complex systems where the engine and transmission are closely linked. An immediate professional diagnosis is recommended if you’re experiencing transmission issues alongside a flashing Check Engine Light.

Can a Fuel Pump Cause the Check Engine Light to Flash?

While a faulty fuel pump won’t typically cause the Check Engine Light to flash, its failure can lead to engine problems like misfires, which can trigger a flashing light. If the fuel pump is unable to supply sufficient fuel to the engine, it could result in an imbalance that causes the engine to misfire and subsequently cause the Check Engine Light to flash.


As I’ve explained, a flashing check engine light indicates severe engine issues that demand immediate attention. Ignoring it or delaying action is not an option; doing so could escalate the problem, leading to more significant damage and costly repairs.

Safely parking your car, observing any unusual symptoms, consulting your owner’s manual, and seeking professional assistance are some crucial steps you should take in managing the situation effectively.

While there are various reasons why your Check Engine Light could flash, ranging from severe engine problems to emission control issues, the most common culprit is an engine misfire.

A misfire disrupts your car’s performance puts additional stress on other engine components, and could lead to even more severe issues down the line.