Check Engine Light Flashing? (Here’s How To Fix It)

A flashing check engine light on your dashboard may lead to many questions. Read on to learn everything you need to know when this happens

Flashing Check Engine Light

You drive your car, and suddenly from nowhere, your check engine light starts flashing on your dashboard.

What to do now? Will my car get damaged if I keep driving it? How much will it cost? There could be a lot of questions that may be running through your head.

Luckily, we will cover everything you have to know about a flashing or blinking check engine light in this article. Let’s begin!

What Does A Flashing Check Engine Light Mean?

A flashing check engine light signals an emergency and requires immediate repair. The more you drive with a blinking check engine light, the more damage you may cause to your engine. It is often caused by a misfire due to fuel or spark problems.

The engine control unit monitors all sensors in your car while you are driving, and with this information, it calculates how much fuel should be injected into the engine and at which angle it should fire the ignition.

If one of the values from a sensor is faulty for a short amount of time, it will trigger a trouble code. If the engine control unit gets the wrong value from the sensor several times, the check engine light will appear on your dashboard.

If this problem is severe from a misfire, it will start to flash the check engine light instead. This is to notify you that a problem that may damage the catalytic converter is happening right now.

Check Engine Light

Causes of a Flashing or Blinking Check Engine Light

The most common reasons for a flashing or blinking check engine light include:

A flashing or blinking check engine light is most often caused by misfires and is usually caused by bad spark plugs or bad ignition coils. However, it is not as simple as that because many different things can cause misfires.

RELATED: Will the Check Engine Light Reset Itself?

How to Diagnose a Flashing Check Engine Light?

Mechanics Diagnose Car

So now, that we know what could cause this, where should we begin to pinpoint the problem?

You must understand that every time your check engine light is constantly lightened up or blinking, it will store a trouble code in the memory so you will have a chance to see what was causing the problem.

Therefore it is a terrible practice just to guess which parts could cause the check engine light and start to replace parts. This will, in almost all cases, just make you waste your money.

A much better and more efficient method is to check what the engine control unit is trying to tell us. This can be done with a diagnostic scanner.

You may think that a diagnostic scanner is too expensive for this small problem, and in that case, you can borrow one from a friend or just take your car to a repair shop and let them read the codes for you.

After you have received the engine control unit’s codes, you will most likely find a trouble code related to a misfire. Check for more related trouble codes to continue the troubleshooting on that trouble code.

For example, if you get a misfire trouble code and one related to an ignition coil, you should definitely continue troubleshooting that ignition coil.

If you get misfires on a specific cylinder – check the spark plugs, ignition coils, and wirings. If you get misfires on several cylinders, there is most likely an issue with a too lean or too rich mixture.

Conclusion: Flashing Check Engine Light

A flashing warning light indicates that there is a serious problem with your car’s engine and is usually caused by engine misfires. If left unaddressed, this problem can lead to very expensive repairs.

While it can be tempting to ignore a flashing check engine light if the engine is running fine, it’s still very important to either diagnose it yourself or take your car to a mechanic as soon as possible.

If you see a flashing engine light, but feel that you do not have the knowledge to diagnose the car yourself, do not hesitate to take your car in for diagnosis and repair by a professional.

Learn more:

Find more information in our list of all car dashboard symbols.


Magnus Sellén
Written by:

Magnus is the owner and main author of Mechanicbase. He has been working as a car mechanic for over 10 years, and the majority of them specialized in advanced car diagnostics and troubleshooting. Certified Automotive Diagnostic Technician.