Why is My Check Engine Light Blinking : Causes & Fixes

Check engine light

Many times we see that suddenly the check engine light starts blinking on the dashboard of our car, and without knowing the reason, we do not know why is my check engine light blinking. Actually, there can be many reasons for the check engine light blinking in any vehicle, such as failure of a sensor, wiring issues, or mechanical issues. However, sometimes the check engine light also starts blinking due to an error in the ECU software.

In this post, we will learn why is my check engine light blinking. So that you can examine it thoroughly and make initial efforts to turn it off.

What Does Check Engine Light Mean

The check engine light is a warning indicator displayed on the vehicle’s dashboard that blinks when the vehicle’s onboard diagnostic system detects a problem related to emissions, engine performance, sensor and wiring issues, or any other critical components. In fact, this check engine light alerts the driver that there has been a problem with one of your vehicle’s systems that needs to be repaired. Therefore, an OBD scanner is used to check for any problems in the vehicle’s system, making it clear which part of the vehicle is actually causing the problem.

Why is My Check Engine Light Blinking?

Blinking check engine light can be caused by engine misfiring, ECU malfunction, software error, sensor failure, wiring problem, bad spark plug, ignition coil failure, fuel system problem, catalytic converter failure, or vacuum leak.

Let us know in detail all the reasons for the check engine light blinking so that you can take the right steps to turn it off yourself.

1. Damaged Spark Plugs

Often, worn or bad spark plugs can result in incomplete combustion in the engine’s cylinder, which can lead to engine misfiring and the check engine light blinking due to engine misfiring.

2. Ignition Coil Failure

The ignition coil generates the high voltage required to spark the spark plug. But when an ignition coil fails, it results in a weak or no spark, leading to a misfire in one or more cylinders and causing the check engine light to blink.

3. Fuel System Problems

A malfunctioning fuel system in any internal combustion engine, such as clogged fuel injectors or a bad fuel pump, can disrupt the proper air-fuel mixture ratio, leading to poor fuel delivery conditions, while excessive fuel A rich condition may occur, resulting in both a misfire and the check engine light flashing.

4. Oxygen Sensor Malfunction

In modern engines, oxygen sensors monitor the level of oxygen in the exhaust gases to help adjust the air-fuel mixture and transmit the data to the engine control unit. But a failed oxygen sensor can provide inaccurate readings, leading to improper fuel injection and combustion. This may cause a misfire and cause the check engine light to blink.

5. Catalytic Converter Issues

A damaged or failing catalytic converter in any modern internal combustion engine can restrict exhaust flow and cause backpressure, affecting engine performance. If unburned fuel enters the catalytic converter, causing a misfire, it can overheat, causing the ECU to trigger the check engine light to blink to prevent additional damage.

6. Vacuum Leak

Vacuum leaks in the intake manifold or vacuum hose can disrupt the engine’s air-fuel mixture. Due to this, the fuel combustion process in the engine may be disrupted, causing the check engine light to start blinking.

7. EGR Valve Problems

The exhaust gas recirculation (EGR) valve recirculates exhaust gases to reduce nitrogen oxide emissions. But a bad EGR valve can disrupt the combustion process, causing an engine misfire that can trigger a blinking check engine light.

Why Check Engine Lights are Important?

Check engine lights on the dashboard serve as important indicators of potential problems within the vehicle’s engine system, monitoring various sensors and components and alerting drivers to problems ranging from minor malfunctions to serious problems. Ignoring these warning lights can result in reduced fuel efficiency, increased emissions, and possible engine damage.

In many cases, neglecting this can result in severe engine damage and stalling. So whenever you notice the check engine light blinking in your vehicle, address it immediately through diagnostic tools or a professional inspection and consider a proper repair, thereby reducing the risk of more extensive and costly damage.

What to do When Your Check Engine Light Is Blinking?

A flashing check engine light is an indication that there is a problem with your vehicle’s engine system, which, if not resolved immediately, could result in serious engine damage. However, sometimes there are common causes for the check engine light blinking. But it should never be ignored.

1. Check For Immediate Issues

Whenever the check engine light starts blinking in your vehicle, the first thing you should do is check for possible causes such as a broken wire, a loose gas cap, a visible leak, or anything unusual under the hood. Be careful when opening the hood, as it may be hot.

2. Do Not Ignore Warnings

A flashing check engine light indicates a serious problem that requires immediate attention. Drive the vehicle to a safe location or repair facility. You should avoid driving the vehicle further than necessary. Because if you ignore the check engine light and drive the vehicle, it may damage your vehicle’s engine.

3. Avoid Driving With Warning Lights

You should avoid driving your vehicle with a flashing check engine light unless absolutely necessary. Because continuing to drive may cause more serious damage, resulting in potentially expensive repairs.

4. Use Diagnostic Tools

If you have access to an OBD-II scanner tool, you can plug it into your vehicle’s diagnostic port. The scanner tool will provide you with specific trouble codes that can help identify the underlying problem and make it easier for you to find and troubleshoot the problem.

5. Get Help From a Professional Mechanic

Once you have identified the trouble code with the scanner tool, or if you are unaware of the cause, it is important to seek help from a professional mechanic. Because a qualified mechanic or auto repair shop will have the expertise and equipment necessary to diagnose and fix the problem, they will investigate your problem thoroughly and come up with the appropriate solution.


Q. Can I drive my car with the check engine light blinking?

Nothing can be said with certainty about this because the severity of the check engine light can vary. Sometimes the check engine light may blink for normal reasons, but in some cases, it can also be a serious problem. Therefore, it is better to just take the vehicle to a repair center rather than drive it with the check engine light on.

Q. How do you fix a flashing engine light?

The best step to diagnose this is to scan the vehicle’s systems with an OBD scanner tool. Because this can help you identify trouble codes related to a system-related problem with the vehicle, making it easier to diagnose the problem, make the proper repair, and help reset the scanner tool after the repair.

Q. Can low oil cause the check engine light to flash?

Yes, in many cases, the check engine light may blink when the engine oil is low. But when the engine oil is actually low, an oil warning light is displayed separately on the dashboard, which alerts the driver about low engine oil.

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