Engine Dashboard Warning Light – What Does It Mean and What Should You Do If It Comes On?

by | Aug 18, 2023 | Diagnostics

Engine dashboard warning lights are a cause for concern for many vehicle owners. Its sudden appearance can be alarming, but understanding its meaning and knowing how to respond is essential. In this blog post, we will explore the significance of the check engine light, possible reasons for its illumination and the appropriate steps to take if it comes on.

What is the Check Engine Light and Where is it Found?

The check engine light, also known as the engine dashboard warning light or engine management light, is an indicator designed to alert drivers about potential issues within the vehicle’s engine system. It is usually depicted as an orange or yellow engine-shaped icon on the instrument panel, you will often see it illuminate briefly upon starting your engine in some older model cars.

Located on the dashboard near the speedometer, rev counter or fuel gauge, the engine management light is hard to miss. Modern cars are equipped with onboard diagnostics (OBD) systems, which continuously monitor various components and systems. When a problem is detected, the OBD system within the engine control unit (the car’s main computer) triggers the check engine warning light to inform the driver of the issue.

Smoking exhaust pipe could cause the check engine light to come on

Why Might My Check Engine Light Come On?

The engine management light can illuminate for various reasons, ranging from minor issues to potentially serious malfunctions. Some common causes of engine warning lights coming on are listed below:

  • A loose fuel cap – the fuel filler cap prevents petrol fumes from leaving the fuel tank and keeps the fuel system under the correct pressure so must be done up correctly. This can be immediately remedied by the driver stopping the car and tightening up the cap should they think this is the cause. The engine warning light should go off straight away.
  • Faulty oxygen sensors or mass airflow sensor – this mass airflow sensor monitors the amount of oxygen entering the engine. You will notice a decrease in the engine performance and will need to be investigated by a vehicle technician, drive at a reduced speed to the nearest garage.
  • A malfunctioning catalytic converter – this will need to be investigated by a vehicle technician but may be accompanied by things like dark, smelly exhaust smoke and reduced acceleration.
  • Issues with the ignition system, such as spark plugs or ignition coils or spark plug wires – these will need to be replaced if they are faulty, likely by a mechanic unless you know what you are doing and are happy to undertake the work yourself. This might be the case if you are having trouble starting the vehicle or if it keeps cutting out once started.
  • Other possibilities include problems with the fuel system, emissions control system or issues with the car’s exhaust system or even just an issue with the warning system itself.

Unlike some of the other warning lights it is important to note that the engine management light does not provide a specific diagnosis but rather serves as a general warning. To identify the specific problem, it is necessary to use an OBD scanner or take the vehicle to a qualified mechanic who can perform diagnostic tests to retrieve error codes and diagnose the underlying issue. We carry out advanced car diagnostics and repairs here at Peverell Garage if you are in the Plymouth or surrounding areas.

Red stop sign - a flashing or red engine management light means you must pull the car over.

Why would the check engine light be flashing?

If the check engine light illuminates but is flashing, it indicates a severe issue that requires immediate attention. The most common reason for a flashing engine management light is an engine misfire. This occurs when the fuel and air mixture in one or more cylinders doesn’t ignite properly, leading to an imbalance in the engine’s operation. Engine misfires can be caused by various factors, such as faulty spark plugs, ignition coils, fuel injectors or a malfunctioning sensor.

Ignoring a flashing engine light can lead to more significant damage, such as damage to the catalytic converter or other engine components. If you observe a flashing engine light, it is crucial to pull over safely, turn off the engine, and have the vehicle towed to a qualified mechanic for immediate diagnosis and repairs.

In such a case the flashing light may be accompanied by the word ‘STOP’ illuminated in red on the dashboard or may instead have a red engine management light. This indicates a serious malfunction and again you should pull over as soon as it is safe to do so and not drive the car until it has been checked over by a qualified mechanic.


Man in blue overalls stood next to engine from white car doing car maintenance

What Should I Do If My Check Engine Light Comes On?

If your check engine light comes on, it is crucial not to ignore it. Even if the vehicle appears to be running normally, there may still be an underlying issue that requires attention. Here are the steps you should follow:

  1. Check for obvious problems: Before panicking, ensure that the gas cap is tightened properly. A loose or damaged gas cap can trigger the check engine light. If the light persists after tightening the cap, move on to the next step.
  2. Assess the vehicle’s behaviour: Pay attention to any changes in performance, unusual noises or abnormal vibrations. Take note of any specific details that might help the mechanic in diagnosing the problem.
  3. Visit a qualified mechanic: It is advisable to seek professional help to diagnose and resolve the issue. An experienced mechanic can use specialised diagnostic tools to retrieve error codes and perform necessary repairs.

Can You Still Drive with the Engine Light On?

In general, if the check engine light is steady or not accompanied by any noticeable changes in vehicle behaviour, it may be safe to drive to a mechanic for further assessment. However, it is recommended to have the vehicle inspected as soon as possible to prevent potential damage or costly repairs.

On the other hand, if the check engine light is flashing or a red engine light appears, it signifies a severe problem that requires immediate attention. A flashing light usually indicates an engine misfire, which can lead to catalytic converter damage or other serious issues. In such cases, it is crucial to pull over safely and have the vehicle towed to a mechanic to avoid further damage.

Come to Peverell Garage to diagnose and fix any issues associated with your check engine light

The check engine light serves as an essential warning system, alerting drivers to potential problems with their vehicles’ engines. Understanding the significance of this warning light and knowing how to respond can help ensure the safety and longevity of your vehicle.

Always consult a professional to diagnose and resolve any issues indicated by the check engine light promptly. If in doubt, give us a call here at Peverell Garage on 01752 266099 to see how we can help you today.

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