Check Engine Light Flashing – Meaning, Causes (& What to Do)

You’re cruising along the highway. The car seems to be running fine, and you’re minding your business. But suddenly, you notice the check engine light flashing. 

As you’re staring at the blinking dashboard light, you get a sinking feeling in the pit of your stomach, and a million questions start running through your head. Why is my check engine light flashing? Can I keep driving? Will my car get damaged? How much will it cost? Will it turn off by itself?

If you find yourself in this situation, and you don’t know what to do, don’t worry. We will explain and cover everything you need to know. So, Let’s start!

What Does a Flashing Check Engine Light Mean?

A flashing check engine light is a sign of a severe problem and an indication that your vehicle requires immediate repair. Though, the main purpose of a flashing check engine light is to warn you that if you keep driving, you may cause further damage to your engine. It is often caused by a misfire.

The engine light is a great car safety feature to let the driver know that something is wrong. and although it is easy to panic just by reading “severe problem”, you can save your car from further damage thanks to this dashboard light popping up. But why is it flashing?

Why Is My Check Engine Light Flashing?

The most common reason for a flashing check engine light is a misfire caused by fuel or spark problems. However, many things can cause a misfire, so the best way to pinpoint the cause of your blinking check engine light is to connect your car to a diagnostic scanner to check for trouble codes.

This is possible thanks to your vehicle’s self-diagnostic feature. It is called the on-board diagnostic (OBD) and constantly runs tests to track and alert the driver to problems. If it fails two tests in a row, it illuminates the check engine light to let you know there is an issue that needs to be addressed.

Here’s an example.

The engine control unit (ECU) constantly monitors all the sensors in your car by reading their values. This information is then used to calculate and adjust the engine actuators, such as the fuel supply, ignition timing, and idle speed, to ensure optimal engine performance.

These value readings are very precise, and if the values from one of the sensors are faulty for a short period of time, the on-board diagnostic system will notice and trigger a trouble code. If the engine control unit keeps reading the wrong value several times, the check engine light will illuminate on your dashboard.

Suppose this is caused by a misfire that is severe enough. The check engine light starts to flash or blink to warn you that a problem that may be damaging your engine or catalytic converter is happening right this second.

Check Engine Light Flashing vs Solid

solid check engine light usually means a less serious problem, and you can continue driving if there is no change to how the car runs. However, you should still get it checked out as soon as possible.

A flashing check engine light means a severe problem may be damaging your engine right now, and you should immediately pull over. Usually, the more you drive with an engine light blinking, the more potential damage.

So what can cause a flashing check engine light? Let’s find out!

Causes of Flashing or Blinking Check Engine Light

  • Misfires (most common)
  • Faulty spark plugs/ignition coils
  • Faulty engine sensors
  • Faulty EGR valve
  • Faulty or Bad fuel injectors
  • Faulty oxygen sensors
  • Faulty crankshaft or camshaft sensor
  • Exhaust emission problems
  • EVAP trouble codes
  • Boost or overcharging problems
  • Internal engine problem

If the check engine light flashes, it is most often caused by engine misfiring on one or several cylinders. But if you are unsure whether or not this is the cause, there are a few signs you could look for. Keep an eye on the following symptoms:

Symptoms of a Misfire

Car shaking or vibrations: If your check engine light is flashing and your car is shaking while accelerating or speeding up. There is a big chance of misfiring cylinders.

Sluggish or Jerky Acceleration: If your car is not accelerating like it used to or feels jerky, it might be misfiring. Make sure to get it checked out.

Rough Idle: A rough idle is also often caused by a misfire If your check engine light is flashing and the car is idling roughly, it is time to take it to a mechanic.

Sudden Engine Sound Changes: If you notice any strange noises coming from your engine bay, like coughing, clanking, or sputtering, it could possibly be a sign of interrupted internal combustion due to a misfire.

Although these are all signs of your car misfiring, it’s not simple to determine what is causing the misfires and the flashing light. But it’s usually due to ignition problems

How to Diagnose Check Engine Light Flashing

Now that we know what could cause the flashing check engine light, it’s time to determine it. But diagnosing it by guessing which parts to replace would be expensive and inefficient.

Every time the check engine light is flashing or blinking, your car stores a trouble code, also called an error- or fault code. It tells us what it was that triggered the code.

So if the engine light is either on or blinking, it’s a much more efficient and better method to address the root of the problem with a diagnostic tool called an OBD2 scanner.

If you don’t want to spend money on buying a diagnostic, you can take your car to an auto parts store or repair shop and ask them to read the codes for you or make a full professional diagnosis of your car by a qualified technician.

Final Thoughts – Check Engine Light Flashing

If you’re driving and your check engine light starts flashing, it’s important to pull over and turn off the engine as soon as possible.

A blinking check engine light is often caused by a misfire due to fuel or spark problems. However, there can be many different causes of a misfire.

The best way to determine what is causing the problem is with an OBD2 scanner that can read trouble codes. But if you don’t want to spend money on a diagnostic tool, you can take your car to a mechanic or auto parts store, and they can read the codes for you.

Remember, it’s always better to be safe than sorry to avoid costly repairs. If you are ever unsure about what to do, it’s always best to consult a professional.


What Does a Blinking Engine Light Mean

Your check engine light’s purpose is to let you know when your vehicle has a problem. When the light starts flashing, it indicates a high-level warning and means that your car needs immediate repair. If you keep driving, it could further damage the car.

Can You Drive With a Flashing Check Engine Light?

You should not drive with a check engine light flashing or blinking. The light indicates that damage to your engine or other parts, such as the catalytic converter, is happening right now. Therefore, driving with a blinking check engine light could cause further damage and serious problems, so it’s best to get it checked out

How Long Can You Drive With a Blinking Check Engine Light

It’s not recommended to drive at all with a blinking check engine light. If the light is flashing, your car is likely misfiring which could cause damage to the engine or other parts if you keep driving. The longer you drive, the more damage that can occur.

Why Is My Check Engine Light Flashing Then Stops?

If your car’s check engine light is flashing several times but then stops, it usually means the emission control system is not fully ready yet. This is not a cause of concern and should not be confused with the high-level warning of a continuously flashing check engine light.

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Rickard Cefalk

Rickard is the owner of and a dedicated and avid do-it-yourselfer who has always enjoyed working on his own vehicles since childhood. He now devotes his time to sharing his expert knowledge of car maintenance and other car-related information through his website.

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