Updated at: 14-07-2022 - By: Lucas

The check engine light, a part of the car’s computer

A diagnostic system known as OBD II has been in use for more than two decades on automobiles. The previous generation has been enhanced and standardized in this iteration.

The On-Board Diagnostics (OBD) system in your car illuminates the Check Engine light when a problem arises. Your car’s computer, the Electronic Control Unit (ECU), controls this system.

It is possible for sensors or actuators that monitor the engine’s performance or emissions to detect issues such as a misfire, a lack of fuel injection, an abnormal output voltage to the ignition system, or a malfunctioning fuel pump. When your car’s electronic control unit (ECU) detects an issue, it will initially attempt to fix it or wait a few cycles.

When does the check engine light error keeps going on and off intermittently?

Check Engine Light Comes On And Off-2

If the computer is unable to fix a problem, it will store a difficulty code in the ECU’s memory, which will activate the check engine light on your dashboard, especially if the problem is engine-related. You may read this code by connecting the OBD to the computer in your car.

The check engine light will light up in a variety of ways when a problem is found that requires further investigation.

Intermitent check engine light, it keeps going on and off

This issue may be the result of a breakdown in software or on a component of the vehicle, but it might also be the result of an error. In some cases, the check engine light will flash sporadically, going on and off, and then stopping and starting again. Only in limited circumstances does the issue arise. When a car goes over a bump in the road, a loose connector or broken wire may keep connecting and disconnecting, causing the lights to come on and go out again.

However, rather of jumping to a more sophisticated diagnosis right away, you should consider starting by screening for this problem first.

Check engine light stays always on

Check Engine Light Comes On And Off-3

Check engine lights are often a sign of a significant problem, although this is not always the case. A filthy or defective mass airflow (MAF) sensor, for example, or faulty spark plugs are frequent culprits. Until you clean or replace the sensor or spark plugs, the check engine light will continue to illuminate.

As an example, the check engine light might be caused by a wide range of issues with the vehicle.

Check engine light is flashing constantly

There are a variety of reasons why the check engine light can be flashing on and off incessantly, and if left unattended, it might lead to major damage.

If the engine is misfired, fuel can enter the exhaust manifold and then be ignited by extremely high temperatures. This can result in significant damage to the exhaust system or catalytic converter.

Avoid ignoring these issues before they evolve into costly and time-consuming fixes.

The check engine light is on, but it will turn off itself after a while

It’s also possible to have an engine light error turn itself off after a predetermined amount of time. The Electronic Control Unit (ECU) misinterprets a malfunctioning oxygen sensor’s incorrect signals as a problem with the sensor, which causes the ECU to misdiagnose the problem.

This can also happen if the catalytic converter fails or if other sensors need to be cleaned. Other possible causes include clogged or dirty air filters, as well as broken or damaged hoses or gaskets.

Solutions for an intermittent check engine light error

After a specific period of time, if the check engine light comes on and stays on, it’s time to inspect the engine hoses, gaskets, electrical wires, filters, and spark plugs.

Connect the OBD to your car’s computer to view any errors that have been saved. Having this information will give you a good sense of what’s wrong with the car.

The fact that the check engine light keeps on and off is closely linked to car elements like the spark plugs, catalytic converter, MAF sensor, and oxygen sensor. In order to make the most of these sections, you need pay close attention.

Modern ECUs in cars record more accurate error readings regarding the check engine light, making it easier to find and correct faults. Checking for these issues with unauthorized software and low-cost OBD scanners will only lead to further frustration and may even result in damage to your vehicle.

How to reset the check engine light indicator

The fault codes must be removed from the computer’s memory after diagnosis and correction of the malfunction that activated the light. To erase trouble codes from older cars, simply unplug the battery for a few seconds.

However, if you try this procedure on a newer computer, you risk erasing all of the system settings.

On some car models, the engine may not function properly if the battery is disconnected. When the battery is dead, the electronic control module (ECM) of some newer vehicles can record diagnostic trouble codes (DTCs). The scan tool should be used instead to clear the error light.


In most cases, if a sensor or other issue affects engine performance in any way, the check engine light will come on, and depending on the condition, the error light will behave as described above.

The computer in your automobile regularly checks and adjusts the input values for the appropriate systems using various sensors to monitor and participate in how many emissions are generated throughout the operation of your vehicle.

With today’s automobiles, an ECU is a critical component to the engine’s smooth operation, as it keeps track of all of the vehicle’s primary electrical and electronic components and analyzes the data they send back on a regular basis.

More ECU participation does not guarantee precise error detection and check engine light readings, since it can also have a negative influence by leaving room for errors.