The average modern car has at least 30 different sensors that are all controlled by the Engine Control Unit (ECU). When one of these malfunctions, the ECU reads it as an issue and displays the dreaded engine management light. 

Also known as the check engine light, this is one of the most common and most stressful car warning lights. But what causes the engine management light to come on? And why is it so important to find and fix the issue as soon as possible? Read on to find the answers to these questions.

By the end of this article, you will understand:

  • What the engine management light looks like & what it means
  • What can cause the engine management light to come on
  • If you can drive with this warning light on
  • What you should do if you see the check engine light
  • And much more



The engine management light will appear as a solid amber, flashing amber or red warning light. Red is the most severe, so you should never drive your car if this comes on.

As there are plenty of faults that trigger the engine management light, it's hard for the average driver to pinpoint the issue. What's more, the check engine light can sometimes come on and your car won't lose performance. Even though these faults might not seem too bad, you should never ignore them. You can suffer expensive engine damage and an automatic MOT failure if you keep driving with the check engine light on.

That's why it's so important to book a diagnostic check at a garage near you as soon as possible. This is the easiest way to find and fix your problem and reset the engine management light. 


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What Does My Engine Management Light Look Like?

The engine management light looks like this:


amber engine management light  

This warning light can also show as the words "check engine".


What Does it Mean?

In short, the engine management light is a catch-all warning light. It's designed to alert you that something is wrong, even if your ECU doesn't know what the issue is. Usually, the issue is linked to your car's sensors or electrics rather than a specific part.

The engine management light can come on for many reasons, as we'll discuss later. Some are relatively minor while others are much more severe. The severity depends on the colour of the warning light.


Amber - This is the most common check engine light and is usually triggered by an emissions fault.

While this may be classed as the least severe version of this warning light, that doesn't mean you can ignore it. Some triggers are actually very severe issues that can lead to expensive damage if left too long.

Flashing Amber - This indicates a more serious problem. Your car is at increased risk, especially as it is likely to indicate a misfire within the engine.

Red - This shows the most serious faults and usually means that something vital has failed or is about to fail. You can cause serious damage and put you and other road users in danger if you ignore a red engine management light.


The engine management light is always scary, but it is even more so if it shows up red. So, what causes it to come on in the first place? After all, to fix the issue you need to know what the cause is.


What Can Cause My Engine Management Light to Come On?

Unfortunately, it's not that simple to identify why the light has come on. It's impossible to list all the faults that can trigger an engine management light in one place because there are so many. Plus, many are hard to find without specialist equipment and knowledge of engine fault codes.

That being said, here are 5 of the most common reasons that cause your engine management light to come on.


Ignition System Fault

Any issue with your spark plugs or coils can cause the engine management light to come on. When these get old or develop a fault, they struggle to provide the spark that helps fuel and air combust within the engine. This makes it hard to start your car and can cause a jerky drive or occasional dips in power while driving along.


Oxygen Sensor Malfunction

Modern cars have sensors in their exhaust systems to monitor the oxygen content of exhaust fumes. These ensure that your car is as efficient and environmentally friendly as possible. If too much or too little oxygen leaves your car, or there is a fault with the sensor, the check engine light will come on.

Not enough oxygen indicates that your fuel is burning too rich and too much indicates that your fuel is running too lean.


Mass Airflow Sensor Fault

This indicates that your air filter could be missing, damaged or blocked. Without the data from this sensor, your ECU assumes the engine is getting no air at all and triggers the engine management light. This protects the engine from overheating and serious damage.

Combustion engines need an even mix of air and fuel to work properly and any change to this mixture can cause expensive damage. You may experience rough idling or jerky acceleration if your engine isn't burning enough oxygen during combustion.


Faulty Exhaust Gas Recirculation (EGR) Valve

You might not have heard of this valve before but it's critical to keep your engine running cleanly. Its main purpose is to divert exhaust gases back into the engine where they are burned away.

Issues develop if it becomes clogged with carbon deposits and sticks open or shut. If your engine management light is on and you notice your car is idling roughly, misfiring or you're having difficulty starting it, there could be an issue with your EGR valve.


Contaminated Catalytic Converter

This is a very serious issue which you should fix immediately. The catalytic converter keeps your exhaust emissions as clean as possible and any issue or damage can lead to a very expensive repair if left to deteriorate. 

You might not notice a loss of performance if there's an issue with your catalytic converter. However, it's such an expensive car part that you don't want to run the risk that a serious issue will develop. That's why it pays to get your car looked at whenever you notice the check engine light.


As you can see, some problems that trigger the check engine light don't have any noticeable symptoms, but can be very expensive repairs if you let them deteriorate too far.

That's why it's so important to get the problem looked at and fixed as soon as possible.


Can I Drive With the Check Engine Light On?

We don't recommend driving your car if the engine management light is on.

In some cases, you can keep driving safely. If you have to continue your journey, make sure that your car isn't:

  1. Driving any differently
  2. Making strange noises
  3. Only showing the solid amber check engine light.

Once you arrive at your destination, try and figure out why the light is showing. Contact your breakdown provider for help if necessary.

If there doesn't seem to be an obvious problem, you might think that your car can survive a couple of weeks without an inspection. However, you can cause more serious damage by doing so.


Never Ignore the Engine Management Light

Even if the issue is only minor, there's still something wrong with your car. Ignoring it can make the problem much worse and more expensive to fix.

If the flashing amber or red engine management light is on, you should stop as soon as it's safe to do so and contact your recovery provider. You should never keep driving with these lights on.


My Engine Management Light is On and I Have a Loss of Power - Can I Keep Driving?

A loss of power means that your car has entered 'limp home mode'. This limits your speed, slowing you to a crawl and doing just enough to get you home.

As a result, we don't recommend that you continue driving your car if you can help it, especially as you'll notice the following:

  • Sluggish acceleration
  • A top speed somewhere between 35 and 45 mph
  • RPM limited to less than 3,000
  • Engine management light on

Your engine usually activates 'limp home mode' when it detects a very serious problem. It's a failsafe built in to stop the engine from switching off altogether - so never ignore it.


What Should I Do About This?

You need to get to a safe place. If you have just left home or your place of work, we recommend that you turn back and park your car there. If 'limp home mode' activates midway through a journey, continue to your destination safely and then leave the engine switched off. Don't ignore the issue because your car is still moving.

Once you're in a safe place, book a diagnostic check at a garage near you. Don't try and drive the car to the garage unless you have to. Call your recovery provider and ask them to give you a tow instead.


If driving with the engine management light on is such an issue, you're probably wondering what you should do to get the problem fixed? Well, the answer is quite simple - get a professional to look at your car and tell you what the fault is.


What Should I Do If My Engine Management Light is On?

Understanding why your engine management light is on is a great first step to getting the problem solved. It could be one of any number of issues, many of which are not easy for the average driver to diagnose. This means the best thing you can do is book a diagnostic check at a garage near you. 

A professional technician will use state-of-the-art equipment to scan your ECU and find out what error code(s) it is reporting. They will then use their expert knowledge of these fault codes to translate them and investigate the issue. Once they know what's wrong, they will provide a quote for the repair and get your car back on the road as quickly as possible.

When you book your diagnostic check through BookMyGarage, you get to compare garages like-for-like to ensure you get the best deal near you. You can filter garages by price, distance, availability or reviews and ratings to find the perfect one for you. Then, book your appointment online in just three clicks.

Enter your car reg and postcode into our online booking tool today and book a great deal on car diagnostics near you.


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Why Should I Do Something About My Check Engine Light?

It's vital that you take this warning light seriously.

If nothing else, ignoring the issue could turn a cheap repair into something more expensive later down the line! If your car is struggling to run efficiently, it can put extra strain on other parts. These can suffer more wear and tear and deteriorate faster.

Ignoring an engine management light can also decrease your fuel economy as your engine has to work harder to keep you moving. This means you may need to fill up more often, increasing your fuel bills.

If saving some money wasn't a compelling enough reason to get your engine management light reset, you also run the risk of an MOT failure if you leave it on.


An Engine Management Light Fails Your MOT

If your engine management light is on at all during your MOT inspection, it counts as a major fault - and that means an automatic failure. While this will force you to get the problem solved, it also causes unnecessary stress and means your car has a very avoidable failure on its MOT record.

And that can cause you problems if you want to sell it in the future.

According to a survey we ran in 2021, 78% of drivers said they were more likely to buy a used car if it had a 'clean' MOT history. As 75% of our participants said they checked the MOT history of a car they were looking to buy, that's a lot of drivers who would discard yours over an avoidable failure!

The bottom line is that you need to address the issue that's causing your check engine light to stay on as soon as you can.

Here's how you can reset your engine management light.


How Do I Reset My Engine Management Light?

To reset the engine management light, you must fix the issue that is triggering the warning light. This may mean deleting the error codes stored in the system or replacing a sensor or other faulty part.

Either way, you won't know how to reset your engine management light unless you understand what the problem is. And the best way to do that is to book a diagnostic check at a garage today. A professional mechanic will always know best.

Don't ignore the issue and hope it will go away. Enter your reg and postcode to compare deals and save on car diagnostics near you now.


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