The engine management light (EML), sometimes known as the ‘check engine light’, normally looks like an engine block and appears on the dashboard behind your steering wheel. It’ll light up either amber or red and can be solid or flashing, depending on the issue.
A dashboard warning light is often one of the first signs of a problem with your vehicle. The EML is generally triggered when your car’s sensors detect a potential issue with the engine. At times, the engine management light can turn on briefly when you start your car.
But how do you know exactly what’s causing the EML to come on, and what can you do about it?
Below, we outline some of the causes of the engine management light and what you can do to resolve the issue and continue driving safely.
What does the engine management light mean?
The EML or check engine light is a bit different to other dashboard warning lights because it doesn’t alert you to a specific fault.
It’s common for the engine management light to turn on briefly when you start your engine, but a flashing or continuous light lets you know there might be a problem with the engine. There are several reasons that can cause this, ranging from minor issues to much more serious faults.
Cars have sensors to check everything is running smoothly – if an issue is found relating to exhaust emissions, the sensor will tell the engine control unit (ECU) which turns on the EML. A broken sensor can also turn on the EML.
Of all the warning lights on your dashboard, the EML is one of the most important, so make sure you get your engine checked by a professional mechanic if it’s illuminated or flashing.
Read our complete guide to dashboard warning lights and what they mean.
Which types of engine management light are there?
Your engine management light can tell you there’s a problem in three different ways:
- Steady amber engine management light
A steady amber engine management light represents a less serious issue, usually to do with emissions. You should be able to finish your journey but it’s best to get your car checked as soon as possible.
- Flashing amber engine management light
A flashing amber light is a more serious issue than a steady amber light, and could mean there’s a critical problem affecting the catalytic converter (along with several other issues). Without immediate action you could face a seriously costly repair, so make sure to have your car checked by a mechanic immediately.
- Steady red engine management light
A red engine management light represents a critical issue with your car. If this light comes on and stays on, stop driving and call your breakdown cover provider immediately.
Is it safe to drive with the engine management light on?
Generally, unless there are issues with your engine and you only have a solid amber-coloured EML, you can continue driving to your destination. Have your vehicle looked at by an expert as soon as possible to avoid risking further damage to your car.
If you experience other issues with your vehicle which suggest something’s wrong with the engine (strange noises, a decrease in performance, smoke or strange smells etc.), or the EML is red or flashing while the engine is on, this could indicate a severe problem. If this happens, you should:
- Pull over as soon as it’s safe to do so
- Switch off the engine
- Contact us to report your breakdown so one of our patrols can help diagnose and resolve the problem
We provide 24/7 roadside assistance.
Is the engine warning light serious
Engine warning lights can display varying grades of seriousness. A red or flashing amber engine management light represents a more serious issue than a steady amber light.
No matter which type of engine management light you see on your dashboard, you should take it seriously rather than ignore it – always prioritise getting it checked over as soon as possible.
How long can you drive with the engine management light on?
You’ll normally be able to drive for a while after the engine light comes on (as long as it’s not flashing or red), but try to avoid heavy acceleration and high engine speed. It’s not advisable to drive more than another couple of miles without getting your car checked by a professional mechanic.
Is it legal to drive with the engine management light on?
It’s not illegal to drive with the engine management light (EML) on. However, if you have a flashing amber EML or solid red EML and there are visible issues with your car, you could be pulled over and fined for driving your car in a dangerous condition. It’s generally OK to drive your car if you have a solid amber EML, but only to take it to a mechanic for checks. If you present your vehicle for an MOT with the EML illuminated it may fail the test.
What can cause an engine management light to come on?
There are many reasons for an illuminated engine management light. Some of the most common are listed below.
1. Oxygen sensor malfunction
If the sensor detects issues that your vehicle’s fuel is too rich (not enough air) or too lean (too much air), the EML might turn on.
It may also be illuminated if there's a fault with the sensor.
2. Blocked diesel particulate filter
The diesel particulate filter (DPF) captures and stores exhaust soot to help your engine pollute less.
If there’s a fault with it or the differential pressure sensor, which lets your car know the status of the DPF, the EML light might come on.
3. Mass airflow sensor
The ECU relies on the mass airflow sensor to work out how much fuel to add to the combustion chambers to correlate the amount of air coming into the engine.
If the air filter is missing, modified, damaged or blocked, this can cause the EML to come on.
4. Ignition system fault
If you have a petrol car, problems with your spark plugs or coils may cause the EML to start flashing.
5. Loose oil dipstick
If the EML turns on shortly after you’ve checked the oil in your car, it could be due to the dipstick being loose. Make sure the dipstick has been put back properly and see if that resolves the issue.
Can low oil cause the engine management light to come on?
If your car's low on oil, this is a serious issue that should be resolved as soon as possible. But it very rarely results in the EML switching on.
Low oil has its own dashboard warning light (it usually looks like an oil can) that should alert you to this issue.
Find out how to check and top up your oil.
How do I fix a car engine management light?
There are several problems that may cause an EML to switch on and diagnostic equipment is required to find it. You’ll need to get a mechanic to find and fix the issue so you should take it to a garage as soon as possible.
But if you’re experiencing other issues with your vehicle that indicate an engine problem, or the EML is red or flashing while driving, this suggests a more serious fault so you should stop driving as soon as it’s safe to do so and contact us to report your breakdown.
How to reset the engine management light
If the engine management light comes on in your car, try parking somewhere safe and restarting the engine after 2 minutes. If the light is still on, the only guaranteed way to make sure your engine management light resets and turns off is to take it to a mechanic to get the issue fixed. If you try to reset it another way, you may be ignoring a potentially critical issue with your car.
Will a car’s engine management light reset itself?
The light might reset if the fault is temporary, but if it comes back on you’ll need to take it to a garage so that a mechanic can diagnose and fix the fault. After the issue has been resolved, the light will turn off automatically.
If the EML turns on again after the problem is fixed, you should take your car back to the garage.
You might find that when the EML first turns on, it turns off again after a short while. If it turns off and on intermittently, this is due to the fault only being detected by the sensor at certain times. You should take your car to a garage to resolve the issue and stop the EML turning back on.
Does an engine management light fail an MOT?
An amber or red EML that stays on when the engine has been started is classed as a major fault. This will cause your vehicle to fail its MOT test.
Use our MOT checklist to help pass your next MOT test.
Will the AA come out for an engine management light?
If you have breakdown cover with us you can contact us for advice regarding engine management light issues. One of our technical experts will assess the symptoms and if necessary will arrange for an expert patrol to come to you and carry out tests to fully diagnose the fault. If they can repair the fault at the roadside they’ll do so. Alternatively, our patrol will advise you on the best course of action, which could be to tow your vehicle or follow you to the nearest garage for permanent repairs.
If you’re not a member, it’s still possible to get Roadside Assistance – you can get instant breakdown cover. Simply call us on 03330 046 046.
We'll help you get back on the road.
Why is the engine management light on?
The engine management light only turns on to warn you of an issue with your car, flashing amber or red engine management lights reflect more serious issues that you should try to remedy as soon as possible. The EML turning on can indicate issues with the oxygen sensor, diesel particulate filter, mass airflow sensor, ignition system or a loose oil dipstick, etc.
Why is the engine management light flashing?
The engine management light will only flash if there’s a potentially serious issue with your car, such as a misfire. A flashing amber light is worse than a steady amber engine management light, so make sure to take your car to a mechanic immediately.
Last updated: 01 05 2025 | Author: The AA