Check Engine Light Flashing And Possible Remedies

Check Engine Light Flashing

Typically, a continuously brightened check engine light is normal. However, a blinking check engine light is cause for concern. Furthermore, a flashing check engine light indicates it is a serious issue, and you should get your car to a repair shop as soon as possible. For the most part, if the check engine light flashing is continuous, it could mean trouble.

What Is A Check Engine Light?

For the worst part, the check engine light is a warning. Essentially, it is a light to indicate that the onboard diagnostics system has detected a problem which it cannot fix. From time to time, the issues might be minor, and sometimes the issues might be significant. As long as you have a flashing check engine light, it would help if you had it checked out.

A flashing check engine light, either yellow or bright orange, is indicative of a serious problem. If the light stays illuminated without blinking or flashing, then all is well. While a blinking check engine light might also be a small problem, when ignored, it can lead to a significant problem on which you might spend a lot of money on repair costs.

For every flashing check engine light, there is a problem in the emissions control system. However minor the problem is, the sooner you check it, the better for you. Getting your vehicle towed is cheaper compared to re-building or purchasing a whole engine in the long run. The more you drive with a check engine light flashing, the more damage occurs to your car.

Early diagnosis is critical if you want to continue to drive your car for longer. An early diagnosis can save you thousands of dollars in maintenance. Each diagnostic problem has a different way of diagnosing. Most of the time, it's something simple that takes the least time and effort to diagnose and fix respectively.

What Causes A Blinking Check Engine Light?

There are multiple causes for a flashing check engine light. There are usually indicators that something is wrong with your car, such as not getting enough power when you need it. If your flashing check engine light is coupled with other characteristics, then you might be in trouble. Here are some reasons why you have a flashing engine light.

1) Faulty Oxygen Sensor

If you have a faulty oxygen (O2) sensor, the fuel delivery and fuel combustion will be affected. The oxygen sensor's job is to monitor how much oxygen and unburned fuel is exhausted. When the oxygen sensors have a problem, the airflow is disrupted. Furthermore, the oxygen sensor readings inform your cars' fuel-to-air ratio.

This helps to maximize your cars' performance. Additionally, there are one or two things you can check to confirm whether your oxygen sensor is operating at optimum level. For example, after you check engine light is flashing, your car could be stalling or increased exhaust. Also, a faulty oxygen sensor will slowly affect your catalytic converter, which is terrible for your car.

2) Bad Airflow Sensor

As part of your vehicle's electronic fuel injection system, the airflow sensor is responsible for calculating the volume of air being taken into the engine. The airflow sensor is one of the main components of the fuel injectors system of your car. Therefore, using an airflow sensor in conjunction with an oxygen sensor is vital for efficiency.

Additionally, the car computer uses airflow readings to determine the differences in the automatic transmission. Furthermore, if the airflow sensor doesn't work correctly, the differences in the automatic transmission will be more pronounced. Either way, if your airflow sensor is wrong, it will cause poor acceleration, no start, and the flashing light of the check engine. It can also cause an engine misfire.

3) Lose Fuel Cap

A loose fuel cap is not usually a major cause for concern. Nevertheless, it won't stop your car computer from throwing an error code. However, a loose fuel cap can cause problems in your car's emission system. So while it is very possible to drive around with a loose gas cap, as long as you notice a flashing check engine light, you should take your car in for immediate repair.

A loose fuel cap is essentially problematic because it allows impurities to enter your cars' fuel system. Furthermore, the signs of a loose fuel cap include:

  • Problems tightening the cap.
  • Discoloration around the entry point of the gas tank.
  • A gasoline smell that is ever-present when you drive.

All these and the check engine, light flashing are indicators to change your fuel cap.

4) Worn-Out Spark Plugs

Faulty spark plugs are one of the causes of engine misfires. A spark plug is a device that creates a spark, which ignites the air and fuel mixture in your engine to give it power. For a small device, it is tasked with many jobs. The voltage that the spark plug produces can range between 20,000v to 100,000v. For many reasons, a spark plug is also considered a small thunderbolt.

Some of the symptoms of faulty spark plugs or an ignition system defect include engine misfires which can cause severe damage to your car, slow acceleration, difficulty getting your car to start, and of course, the check engine light flashes. In addition, old spark plugs tend to be faulty; hence they have a problem generating the voltage required to power up the engine.

5) Bad Catalytic Converter

A catalytic converter converts toxic gases from the exhaust gas into less toxic pollutants. While it is possible to drive around without this converter, it is also not recommended. A faulty converter will not affect your engine in any significant way. However, you should pay attention to what your car is trying to tell you.

Some of the symptoms of a faulty converter include a foul smell from the exhaust pipe, overheating under the car, reduced acceleration, and a sluggish performance of the engine. However, the most telling symptom includes dark exhaust smoke. Your exhaust system is one of the important part of your cars' ability to perform.

6) Failed Fuel injector

A fuel injector sprays fuel into the engine's combustion cylinders after it mixes with the air. Driving your vehicle with a faulty fuel injector will automatically cause more than a serious problem. Not to mention it could cause some serious damage to your vehicle. Therefore, injectors should be replaced every 50,000 to 100,000 miles.

Symptoms of a faulty injector include engine vibration whereby your car moves in surges instead of a smooth and gradual movement. Common causes of falling fuel injectors are when debris, dirt, rust, and other foreign materials making their way into the car system. Additionally, the sound of your car will become rougher than usual.

7) Failed Engine computer

An engine computer is tasked with the job of making immediate adjustments to the engine. In most vehicles, the function of the engine computer is to manage the engine timing and managing the fuel-to-air ratio. Furthermore, it relies on information from multiple sensors in order to perform all its primary and assisted functions.

Like any other system, sometimes the engine computer can fail. Additionally, some of the symptoms to look out for include your engine shutting down without reason, a sudden drop in fuel economy, a sudden loss of acceleration and stuttering, or a misfire in your engine. Apart from the usual flashing check engine light, these are some indications of serious damage.

Check Engine Light Codes: What They Mean

The diagnostic check engine light codes are usually divided into four groups. They include:

  • Chassis (C)
  • Network Communications (U)
  • Powertrain (P)
  • Body (B)

For a broader understanding of the meanings of these codes, below are the most relevant codes and what they mean.

a) Engine Misfires (Codes P0300-P0305)

Apart from code P0300, all the other codes in this category let you know that there is a problem with your cylinders. These codes indicated engine misfires in cylinders 1 to 5, respectively. The P0300 indicates that there are multiple misfires in multiple cylinders. Therefore, your mechanic might need to change any cylinder that has a misfire.

b) Sensing Oxygen Levels (Codes P0171 – P0175)

This set of codes has everything to do with diagnosing whether the oxygen levels in the system are functioning correctly. Some of the codes indicate whether the engine is receiving too much or too little air, and some codes focus on the air sensor. If the sensor is underperforming, it will need to be changed out by a certified mechanic.

c) Catalytic Converter (Codes P0420, P0430)

These codes generally report that the catalytic converter is spoilt and needs to be changed. If the catalytic converter is not functioning at maximum capacity, then the check engine light flashing should alert you that there is a problem. Furthermore, the check engine light serves as a warning when the O2 sensors are malfunctioning and affecting the catalytic converter.

d) Evaporative System (Codes P0411, P0440, P0442, P0446, P0455)

These codes appear and are an indication that the secondary injection system has an incorrect flow detected and that there is a complication with the evaporative emission control system. Furthermore, one of these codes could indicate that there is a bad vent control valve, or you have a loose gas cap that also needs to be replaced.

e) Exhaust Gas System (Codes P0401)

This trouble code shows that there is a complication with the exhaust gas recirculation system. It indicates that the system is not functioning sufficiently. Different components come together to ensure that there is sufficient recirculation of exhaust gas so that there is no release of very toxic gases into the atmosphere.

Types Of Engine Light Illuminations

As we have previously stated, the check engine light acts as a warning system that there is a problem with the car system. It can be a minor problem, or it can be a major problem. Therefore, there are ways to determine whether you need to pull over immediately and call a tow service or keep driving and take your car in for diagnostics in a few days.

There are at least three ways to know what your check engine light means. Therefore you need to pay attention to how the check engine light illuminates at different times and if your car is still running smoothly, or you can get enough power.

i) Continuous Engine Light Flashing

This is usually a bad sign. If your check engine light is always blinking or flashing continuously, you should pull over immediately and call a local tow service. If the check engine light blinks continuously, it is indicative of a severe problem with the engine. A rapidly blinking light is one of the things that most drivers dread because it could mean a costly repair and inconvenience.

ii) Irregular flashing

If the check engine light flashes for a while then stops, it is indicative of a minor issue. Such failures are usually soft failures. A soft failure is an issue such as a loose wire that disconnects and connects. The irregular flashing of the check engine light is dependent on the moment the faulty wire disconnects and connects, respectively.

iii) Continuous Illumination

When the check engine light is continuously on, it means there is a severe problem. However, it is a minor issue that can be fixed without much trouble. You can continue to drive your car for some time with this light on. However, it is always the safest option to go to a professional mechanic for a diagnosis. The problem is usually cheap to fix.


You should know that as long as your check engine light is on, there is a problem with your car. Furthermore, as long there is a problem, your car computer will store a trouble code in the memory. From there, you can know how to proceed. Furthermore, you should also use a diagnostic scanner to ensure you are taking care of the right problem.

Additionally, it is possible to drive your car with a blinking check engine light; however, it is never advisable. The sooner you can have the check engine light looked at, the better for the health and performance of your car.