Check Engine Light Flashing: What Does It Mean  

When the Check Engine Light turns on, a lot of you may instantly panic. This is especially true in the case of inexperienced drivers or those who do not have much technical knowledge. It can mean different things. Regardless of what it means, the important thing is to act the soonest possible time to make sure that the problem does not escalate.

In the rest of this post, you will learn more about the meaning of Check Engine Light flashing. It is important that you know these things so that you will know how to act accordingly and to prevent the engine from being more problematic.

Check Engine Light Flashing
What is a Check Engine Light?

Before discussing what it means when the Check Engine Light is flashing, allow me to give you a quick discussion on what it actually does and what it is. Also known as Malfunction Indicator Lamp, this is connected to the engine’s computer and is meant to send an immediate warning that there is something wrong.

It is one of the most important components of the On-Board Diagnostics system of your car. When a problem is detected, the light blinks or flashes. In most instances, it will turn to yellow. Once you are confronted with such situation, you need to act as soon as possible. As many would say, when the Check Engine Light flashes, it simply means that you have to do something NOW.

It is also important to note that a flashing Check Engine Light means a different thing when the light is solid. If it is flashing, this is an immediate concern, which means that you should immediately pull over and deal with the problem.

Meaning of Check Engine Light Flashing

In this section, allow me to walk you through some of the problems that can be apparent when you see a flashing Check Engine Light from the dashboard.

Poor Catalytic Converter

Among others, the problem can be because of a poor catalytic converter. In case you do not know, a catalytic converter is one of the most important parts of the exhaust system of your vehicle. The failure of the converter would mean major repair and a costly replacement. While it is a rugged component, it can still be prone to wear and tear.

One of the reasons why the catalytic converter replacement is expensive is because of the precious metal used in its construction. This metal can be damaged as a result of engine misfire.

Failure of the Oxygen Sensor

The oxygen sensor is located in the exhaust manifold and has the primary purpose of monitoring the amount of unburned oxygen. It gauges the fuel mixture, allowing the computer to know if it is burning less or more oxygen. This makes it possible to correct the mixture of oxygen and fuel that is used by your vehicle.

If this is the reason for Check Engine Light flashing, you need to correct the problem early on as this is important in the improvement of fuel economy. To add, if it is not repaired as soon as possible, this can also increase the damage to the catalytic converter. Replacing this sensor will make sure that the engine will deliver its peak performance.

Damaged Mass Air Flow Sensor

The Mass Air Flow Sensor is another important component for the performance of the engine and gas consumption. It also minimizes the emissions that are produced. It has the main purpose of determining the amount of air that enters the engine. These components can be fragile, which is why it is a common component to check when the engine light is blinking.

One of the most common reasons for the failure of this component is the improper installation of the air filters. If you do not replace the filter, the mass air flow sensor can also be damaged. To prevent the sensor from malfunctioning, make sure to regularly check the air filters and have them replaced at least once in a year.

Faulty Spark Plugs and Wires

The flashing of the Check Engine Light can also be indicative of serious problems with your spark plugs and wires. When these parts are fouled, engine misfire is possible, and this can be a huge problem. The cost of the replacement of these parts can depend on the car that you have or the company that will be executing the repair job.

Failure of Ignition Coil

The function of the ignition coil is to convert the low current into a higher voltage, which is an essential for the ignition of the fuel and for the engine to start. Aside from the Check Engine Light, other symptoms of this problem include backfiring, engine misfiring, reduced fuel economy, engine jerking, and vehicle stalling.

Damaged Gas Cap

This problem is very common, but thankfully, this is also one of the cheapest and easiest to repair. In some cases, you do not even need to have it replaced. Just tighten the gas cap to avoid the evaporation of the fuel. Aside from flashing of the engine light, a good way to determine the presence of such a problem would be when there is a foul smell from the engine.

What to Do

The first thing that you need to do is to pull over as soon as you have the chance to stop. Do not ignore this warning as this can compromise the performance of your car and more importantly, your safety. Once you have stopped, perform a further diagnosis to remedy the problem.

In some cases, it would appear that the car is perfectly fine, even when the Check Engine Light is flashing. If you continue driving, different components can be prone to burning and this can lead to significant engine damage.

Aside from driving slower, the reduction of the load of the vehicle can also help. If you are towing a trailer, for instance, stop as soon as the engine light flashes.

If you want an easy way to determine the problem and execute the necessary solution, you should invest in a scan tool. This will be helpful in performing an accurate diagnosis of the problem. The tool will reveal several codes, which you have to know how to read to see what is the actual problem.

Perhaps, the best thing to do is to go to the nearest mechanic. The pros have the expertise that will be important in determining the actual cause of the problem and they know the best things that can be done to have the perfect solution.


In sum, a Check Engine Light flashing is an indication of a serious problem. As shown above, it can be an indication of problems with spark plugs, wires, ignition coil, gas cap, oxygen sensor, and a catalytic sensor, among others. Do not ignore such a problem to make sure that the engine will deliver its peak performance all the time.

Have you ever experienced a flashing Check Engine Light before? What is the cause and how did you solve it? Is there anything else that you would like to add? Feel free to leave a comment below.

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