What to Do When Check Engine Light Comes On?

Do you feel panicked whenever your car check engine light comes on? Learn what to do when check engine light comes on and off while driving. Discover common causes, potential dangers, solutions, and tips to stay safe on the road.

Are you one of those car users or drivers who don’t like ignoring the check engine warning light? If yes, driving with the check engine light on could be a nerve-wracking experience for you.

Don’t worry; you aren’t alone; it can be stressful and confusing for anyone car owner who doesn’t know what does it mean when the check engine light flashes.

Whenever you find a check engine light comes on and off while driving, it’s vital to pay attention to that light. You should immediately contact your auto mechanics shop to sort out the issue in such a situation.

what to do when check engine light comes on
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Even so, the car’s electronic system has various light indicators with different meanings. Since certain technicalities are involved with the indicators, it sometimes becomes difficult for drivers to tell what does a flashing check engine light mean.

That’s why most of the time, they usually ignore it. However, ignoring the check engine light might cause some serious trouble with your vehicle’s engine in the long run.

But you shouldn’t worry too much, as this comprehensive guide will help you understand what causes check engine light to come on and off intermittently and what to do when check engine light comes on after driving for a while. We have listed all the possible helpful steps to diagnose the issue and possible solutions.

What Does the Check Engine Light Mean?

Most car users often wonder; what does a check engine light mean and what does it mean when the check engine light flashes. If you are also one of them, let’s learn; what does check engine light indicate?

The check engine light on the dashboard is mainly a warning indicator. The check engine light is a sign that comes when the onboard diagnostics system or also known as (OBD II) has identified an issue in the vehicle’s emission, engine, fuel, or other essential parts.

The malfunction might be due to quite basic problems like a loose gas cap, a defective oxygen sensor or sparking electric plugs, or something as serious as a catalytic converter or engine malfunction. Whatever the issue, it’s better not to ignore it.

All cars and light trucks have installed diagnostics systems that distinguish engine-related issues that influence the emission control system.

The check engine light commonly appears as an engine’s yellow or orange icon with a “Check” or “Service Engine” word that ought to come on for a couple of moments whenever you turn on the engine with other warning lights. However, if the light stays on, there is an issue.

If there is a flashing check engine light or blinking, it demonstrates a significant problem that should be handled immediately. Some main solid check engine light causes can be basic and straightforward to settle; however, in some cases, an engine light means some server issues.

Must check: 13 Reasons Why Your Check Engine Light Comes On and Off

What to Do When Check Engine Light Comes On?

Most vehicle owners get confused or panic when they suddenly notice the check engine light come on. It mainly happens because they don’t know what to do when the check engine light comes on and off.

But we suggest you don’t let this warning signal stress you out. It would be best if you never panicked or overreacted to the situation. A check engine light or engine service indicator warning appears quite often in almost all vehicles and can be easily fixed.

Ignoring the check engine light can lead to more severe and costly problems down the road, so it’s essential to address it promptly. And since calling the auto mechanic could be a slow process. Therefore, taking instant yet effective steps to tackle the issues is a wise decision.

Check out some of the crucial steps to know what to do if check engine light comes on. These solutions will help you keep your car running smoothly and avoid unnecessary expenses. Here we go:

Make Sure the Gas Cap is Tight

The defective gas cap is one common and main culprit that triggers the car engine light. Thus, your gas cap is the foremost thing you should examine when your check engine light comes on.

Check whether your gas cap is loose, or sometimes it can also get cracked or broken for several reasons. If the gas cap is loose or not secured properly, try to tighten it. If the condition of the gap cap doesn’t seem appropriate to use, replace it immediately with a new one to avoid further damage. If it remains defective, the fuel will evaporate.

In this case, it’s essential to understand that the light may not switch off for a few trips once you fix the cap. You can take a chance while driving during this time to check whether the light switches off. Besides this, performing a diagnostic test is also advisable later.

Check for Low Oil Pressure

The low oil pressure is the next thing you can check when the engine light comes on. Low oil pressure usually overheats the vehicle, worsening the situation while driving. Thus, Investigate your gauges and lights for low oil pressure.

The low oil detected by the onboard diagnostic system can appear as a check engine light going on or off. If the car check engine light is flashing, slow down your vehicle and quit towing.

In case of such an issue, it would be better to instantly pull over your car and call for a tow truck. Driving any long can directly affect the vehicle’s engine, cutting your pockets financially.

Check Your Car’s Engine Temperature

If the things mentioned above aren’t working, the chances are that your car check engine light coming on due to overheating. The car’s engine temperature also reflects some other signs.

For example; the temperature gauges running high or, in the worst condition, the smoke emerging from under your hood. Since it could be an extreme malfunction with the engine, you must tackle it immediately.

In such cases, reducing the carload is better; if you are towing something, stop it immediately. Turning on the radiator as a method for releasing some heat from the engine would be wise.

If this doesn’t work, you might have to pull over and call for emergency assistance from mechanics; if you see a car check engine light.

Look for Unplugged or Loose Wire

Another solution you must try when the engine light comes on is checking loose or unplugged wires. Within time, car wires get loose or destroyed by an external power, such as a mouse or squirrel, which can immediately set on the car check engine light.

Further, the broken wires often cause instability in voltage while starting the engine, as the spark is responsible for making it happen, and broken wire causes trouble in spark plugs.

When both of these are compromised, your engine can’t proceed either; you might have less power and lower mileage, and your engine light misfires, among other issues. Thus, whenever checking the engine light on, ensure all the engine wires and spark plugs loosen tight the wires.

In a broken condition, replace them with new wires for proper electric circulation via spark plugs to ignite the engine.

Reduce the Speed and Load Size

Another prompting method for addressing the car check engine light is ensuring the vehicle’s speed and reducing the vehicle’s load. In any case, if you find out the low performance of the vehicle and low mileage performance, driving with check engine light on could be harmful.

Thus, decrease your vehicle’s speed. If the check engine light appears flashing while driving, a leading and effective solution is driving slowly. It will automatically give some relief to the engine. This is particularly vital if the check engine light is flickering or appears red on the dashboard, indicating a more pressing issue.

Besides, carrying heavy loads or towing something with a vehicle puts pressure on the engine and high-speed traveling. Thus, you can likewise reduce the pressure on the engine by decreasing the load it carries.

Perform a Diagnostics Test

Another important step you ought to do when a car check engine light comes on is to conduct a diagnostics test. The check engine light is an outward-facing section of the vehicle on the diagnostics system.

Simply put, it is an internal section of the computer system of your vehicle that is responsible for examining the issues. To comprehend the massive size of the potential problems that could emerge. There are a lot of diagnostics apps that test the engine system.

In such a situation, if you’re wondering what to do when my check engine light comes on? Based on your decision and level of expertise, you can possibly use the OBD1 or OBD2 diagnostic tool to find what specific issue set off the check engine light in the system.

Avoid Emissions Testing

Ensure avoiding the emissions testing until you’ve completely tackled your car check engine light issues. Emissions testing is essential in many states to guarantee that your vehicle doesn’t emit excessive carbon into the environment.

A check engine light will be an alarming issue that could make you fail the emission test in certain conditions. Whereas some consider the light to be on as an automatic fail. This is valid whether a loose gas cap or wire just set off the light.

You might have to drive the vehicle for a few miles to pass the emission test whenever you’ve settled the issue. Driving 50 to 100 miles is generally sufficient for the system to reset.

Get the Check Engine Codes Read by a Professional

The final yet effective way to tackle when the check engine light comes on after driving for a while is approaching a profession. Whenever a check engine light appears, it mainly results from a diagnostic trouble code or a DTC.

To examine the exact meaning of the codes, take your vehicle to a nearby auto mechanic shop and request to explore the diagnostic test codes of the car.

A professional mechanic will utilize a particular device to figure out the code that makes the engine light turn on. In any case, remember that these codes are just a small section of the fight.

You’ll, in any case, have to get your car analyzed by a professional if you truly desire to fix the issue. Regular maintenance will ensure that your check engine light backs its head as quickly.

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8 Reasons Why Check Engine Light Comes On

Never panic whenever you see your car check engine light keeps coming on and off because an engine warning light doesn’t always mean that it will cost you a lot. Problems that trigger a check engine light are usually basic and can be fixed quickly. However, never ignore it; examine the issue soon after you discover a warning.

For your ease, here are some of the most common reasons why does my check engine light comes on and off, which will ultimately help you detect them quickly. Let’s check them out:

Cause #1: Loose Gas Cap

The foremost reason could be the gas cap if it’s loose or broken. A defective gas cap can make a car check engine light come on as the vehicle’s onboard system detects the losing pressure in the gas tank.

A gas cap is reliable for maintaining pressure inside the tank, preventing gas evaporation, and preventing vapor from being delivered into the air. If you have just filled the gas, and the engine light appears, check the gas cap and put it back tightly, which might determine the issue.

Cause #2: Oxygen Sensor Malfunction

The oxygen sensor (also known as the O2 sensor) monitors the unburnt oxygen in a car’s exhaust system. The malfunction of O2 would disrupt the engine from running. However, it will consume more fuel than expected.

In the long run, a faulty O2 sensor can harm parts like spark plugs and catalytic converters and even reduce fuel efficiency. So, whenever you detect a check engine light coming on and off, look for the Oxygen sensor once.

A typical O2 sensor might cost you around $175, with the labor cost depending upon the vehicle’s model.

Cause #3: Bad Spark Plugs or Plug Wires

Have you ever experienced the usual car startup process, or if you detected that your car isn’t speeding up normally as it is meant to? These things can both be caused by spark plugs in bad conditions.

Broken spark plugs or plug wires can impact your engine’s combustion process. It can likewise prompt a check engine light come on and off.

The faulty spark plugs wouldn’t completely prevent you from driving, as you can cruise all over with them. However, once they get more terrible, you will see the issues with your car pile up. Thus, if you ever detect a check engine light keeps going on and off, then check the spark plugs

Cause #4: Faulty Mass Airflow Sensor

If you are inspecting why did my check engine light come on, it might be a faulty airflow sensor. The amount of air entering the car will decide how much fuel is required to run efficiently.

The main role of the mass airflow sensor is to examine the air and guide the car’s computer system on how much fuel it needs.

Whenever a mass airflow sensor isn’t working as expected, a few elements will disturb the engine performance and lower the fuel economy. Yet, if even ignored, this can damage the spark plugs, oxygen sensor, and exhaust system.

Cause #5: Dead Car Battery

A dead or old car battery could be why the check engine light comes on after driving for a while. Whether the maintenance or non-maintenance batteries, people usually forget to take care of the battery.

The battery life is up to 5 years, and after that, the battery power drops down to less than half, which causes trouble while engineering the engine.

If you ever notice an interrupted engine ignition process or a car check engine light coming on while starting the car, it could be due to a dead battery.

Thus, open the hood, disconnect the battery wires, and connect again to see if the problem solves. If not, you might need to replace it with a new battery before it causes more trouble.

Cause #6: Bad Catalytic Converter

Catalytic converters are mainly used to control the emission from the exhaust of cars. The main function of the catalytic converter is to convert harmful carbon monoxide into carbon dioxide.

And without this significant ability, your car won’t pass the vehicle carbon emission test required according to driving law.

A defective or clogged catalytic converter could be one of the reasons why check engine light comes on. However, it also impacts the fuel economy and causes your car to have a sweltering temperature. Thus, check with a catalytic converter whenever your car check engine light comes on.

Cause #7: Exhaust Gas Recirculation Valve Failure

The exhaust gas recirculation EGR system helps decrease the amount of nitrogen oxide that emerges from the engine and assists it with running more proficiently.

It coordinates the hot exhaust gasses back to the ignition chambers, which ignites fuel easier. It additionally decreases emissions.

The EGR valve sometimes gets stopped or fails to cause the car check engine light to come on. Thus, if you have some technical knowledge, you can easily clean and reinstall the valve.

Cause #8: Vacuum Leak

Vacuum pressure is used by the car emission and even braking system to function. The vacuum draws from Hoses and valves from the engine’s manifold.

Whenever any of the hoses break or be dislodged, or in case the valve gets stuck open, it will be detected by the car’s onboard diagnostic system and could be one of the reasons why check engine light comes on.

In this case, you will find the engine idling quicker, running harshly, slowing down, or making weird sounds. Fixing the issue could be a streamlined process, as reconnecting a hose or replacing it with a new one would solve it.

Must check: How to Tell If Engine is Damaged from Overheating (8 Ways)

How Long Can You Drive with Check Engine Light On?

Is it safe to drive with a check engine light on? How long can you drive your car with the check engine light on? These are among the most asked questions by people who wish to know what to do when check engine light comes on and off while driving.

The answer to this could be confusing, or it could also depend upon how extreme the issue is that makes the check engine light come on. However, you can drive it for 80 to 100 kilometers in normal situations. But it is wise to drive on separate trips of 3 or 4 for 100 km. The check engine light usually comes on when a part in the system framework is failing or not working, and a sensor will detect and indicate to you via engine light to come on.

If you wonder, can you drive with check engine light on? Never drive more than 100 miles, even in three or four trips. After each trip, switching the engine off allows the vehicle’s computer management system to check its parts and evaluate where the issue is coming from.

You can drive it securely as long as your vehicle isn’t performing oddly. However, in between the trip, keep checking on a few common issues mentioned above at your end until you reach a mechanic. If you ignore the engine light and keep driving the vehicle without settling the issue, it could damage the vehicle or cost you extensively more.

What to Do When Your Check Engine Light Comes On?

The car check engine light offers an ideal chance for the driver to get alarmed regarding his car’s issues and is considered the vehicle’s signal for support or quick attention. It is essential to give proper attention to the car’s condition for a smooth driving experience.

Never hold on until the vehicle lets the check engine light come on. It is fitting to make occasional check-ups to ensure everything is set up.

However, in case you have to face sudden check engine light comes on while driving, then never forget to follow a few critical inspection steps; check for the car’s engine temperature, reduce the speed and load, and last, always perform a diagnostic test to examine the issue and fix it.

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About Jace Cuban

I am an automotive enthusiast who loves to be around cars and pickup trucks. Applying innovative car care products and installing different latest car accessories are my hobbies. Also, I love sharing my adventurous experience with car lovers.

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