Engine Management Light On, What It Means and What To Do

Written by Petro Olekhnovych, mobile mechanic in Aylesham, Kent

The engine management light means your car’s computer has found a fault with the engine, emissions or a sensor. A steady amber light usually means book a check soon. A flashing light means a serious misfire: stop as soon as it’s safe and don’t keep driving. Either way, a lit engine management light is an MOT fail.

What does the engine management light look like?

It’s an engine-shaped symbol on the dashboard, usually amber, and sometimes shows the words “check engine”. When you turn the ignition on it should light up for a moment and then go out. If it stays on once the engine is running, the car has stored a fault code.

Solid or flashing: which is it?

• Solid amber: a fault that isn’t usually urgent. You can normally drive carefully for a short time, but get it checked soon, because small faults can become expensive ones.
• Flashing: usually a severe misfire. Unburnt fuel goes into the exhaust and can quickly damage the catalytic converter. Pull over when it’s safe, switch off and call for help.
• Red, on cars that use a red light: treat it as serious. Stop safely and check the handbook. A red warning often relates to oil pressure or overheating.

Not every car flashes the light, so always check your handbook for what your model’s lights mean. For the other symbols, see our guide to dashboard warning lights.

Common causes

• A loose or damaged fuel cap
• A faulty sensor, such as an oxygen (lambda), mass airflow or MAP sensor
• Ignition problems: worn spark plugs, coil packs or leads, which cause misfires
• Exhaust and emissions parts: catalytic converter, EGR valve or diesel particulate filter (DPF)
• Fuel system faults: a blocked fuel filter, weak fuel pump or dirty injectors
• Mechanical faults, including timing problems (when to replace a timing belt)
• Wiring faults or low battery voltage

The light alone doesn’t tell you which of these it is. Only reading the fault code, then checking the part it points to, gives the real answer.

Is the engine management light an MOT fail?

Yes. The official MOT inspection manual lists an engine malfunction indicator lamp that is “inoperative or indicating a malfunction” as a major defect, and a major defect is a fail. This applies to petrol cars and to diesels first used on or after 1 July 2008.

Clearing the light with a cheap code reader just before the test doesn’t fix anything. If the fault is still there, the light comes back, often on the way to the test centre. A pre-MOT check catches this before the test.

Is it safe to drive?

With a steady amber light and the car driving normally, a short careful journey is usually fine. Stop driving if the light is flashing, the car loses power, shakes, smells of fuel, or the temperature gauge climbs. Driving on can turn a small repair into a big one.

How we can help

We come to your home or workplace around Aylesham, Canterbury, Dover, Deal and Sandwich and:

1. Read the stored fault codes with a diagnostic tool.
2. Check the part the code points to, rather than guessing from the code alone.
3. Explain the fault and give you a price on WhatsApp before any repair.
4. Fix it on the spot where possible, then clear the code and confirm the light stays off.

Labour is £30-£50 per hour depending on the job. You can also book an appointment online.

Frequently asked questions

Can I clear the engine management light myself? You can with a code reader, but if the fault is still there the light will come back. Find the cause first.

Will the light go off by itself? Sometimes, for example after a loose fuel cap is tightened and the car has done a few journeys. If it stays on, get it read.

Do I need to go to a garage? No. Most fault-code reading and many repairs can be done at your home.

Need help? Send a WhatsApp to 07563 350335 with your car’s make and model and we’ll come to you.

Sources

• MOT inspection manual, section 8 (GOV.UK)
• Engine management light guide (car.co.uk)