What is an Engine Management Light?

19th Nov 2019

In an ideal world, nothing would ever break on cars and we would keep all of our hard-earned cash firmly in our pockets. Unfortunately, cars throw a curve ball from time-to-time.

One of those curve balls comes in the form of the infamous Engine Management Light (EML), which is designed to warn the driver of any problems with the engine and/or exhaust. In this article, we take a look at what the EML means, why it may have popped up, and how you can get rid of it.

Annoyingly, the EML can appear in three different colours, with each one representing a rough indication of what's gone wrong. Here's a brief look at the possibilities:

Amber Engine Management Light

This is the most common light and is also the least serious. Usually, you will be able to keep driving as normal, but we would recommend having your car checked over by your nearest Evans Halshaw dealership as soon as you can.

Flashing Engine Management Light

This is more serious than the amber light and is usually caused by something that affects the car's performance, such as a misfire. If the light is flashing and your car feels hesitant, we recommend bringing your car to us for diagnostics immediately.

Red Engine Management Light

This is the most severe form of EML and means there is something very wrong with your vehicle. We recommend switching the vehicle off as soon as it is safe and having your car recovered to your nearest Evans Halshaw retailer.

Why has the Engine Management Light illuminated?

There is a number of reasons the EML could pop-up on your dashboard, here are the most common possibilities:


Faulty Oxygen (o2) sensor

The oxygen sensor is designed to reduce emissions by telling the Engine Control Unit (your car's brain) how much unburnt oxygen is leaving the engine through the exhaust. The car will then know if the engine is burning too much/little fuel and adjust itself accordingly. If an oxygen sensor goes faulty, then the car can't operate efficiently, which is why the light appears.


If you drive a petrol-powered car and the light appears, it could be an issue with the ignition system, which essentially creates the spark needed for the engine to run. It could be something as simple as a faulty spark plug, or it could be a coil pack. If the ignition system is at fault, you will most likely notice your car juddering or feeling hesitant while driving.

Fuel cap

Damaged catalytic converter

The catalytic converter is part of the exhaust system and has been designed to reduce the harmful emissions created by your car's engine. A broken/leaking catalytic converter is a major problem that needs rectifying as soon as you can.

Blocked diesel particulate filter

The diesel particulate filter (DPF for short) is fitted to cars that run on diesel (shock) and have been designed to trap soot from the exhaust and therefore reduce emissions. Over time, the filter can become blocked. The problem is usually rectified by taking the car on a dual carriageway and letting the engine "blow-out the cobwebs".

Loose fuel cap

This is probably the most unlikely cause, but it's not unheard of! If your fuel filler cap is loose or missing, then the vapours can escape from the tank. Re-attach the fuel filler cap properly if it isn't on properly and the light should soon disappear.

Is an engine management light an MOT failure?

The engine management light is considered a major fault and will therefore result in your car failing its MOT if it remains illuminated. It's understandable, because if the light is illuminated then it's highly likely your car is either unsafe or nowhere near as efficient as it should be.

Put simply, the issue causing the EML to show needs rectifying before it goes in for an MOT, or it will fail. 

How do I get rid of the engine management light?

Unfortunately, there is no quick or easy remedy for getting rid of the light if the problem has not been sorted on the car. If the light remains after the issue has been fixed, then we would recommend bringing your car into your nearest Evans Halshaw retailer who will be able to clear the code for you.