Dashboard Warning Lights: A Complete Guide for Your Car

Dashboard Warning Lights: A Complete Guide for Your Car

It’s pretty normal for drivers to continue driving with dashboard warning lights on. The fear of large repair bills is enough to put many drivers off taking their vehicles to a garage.  

But failing to take action when your car warns you of a problem can be a costly and sometimes dangerous decision. 

In this guide, we examine what dashboard lights mean and what to do if they pop up. No more ignoring that check engine light symbol! Scroll down to get started.  

1. Check Engine Light

The Check Engine Light or Engine Management Light links to the Engine Control Unit and is displayed if there is a problem with your engine’s performance. Depending on how urgent the warning is, the light can illuminate in different colours.  Here’s a quick overview of each colour: 

  • Yellow, amber or orange – It is safe to continue driving for now, but you should have your vehicle checked soon to keep your engine performing efficiently. 
  • Flashing amber – It may be safe to drive for a short while, but you should book in with a qualified mechanic as soon as possible. 
  • Red – This indicates a serious problem with one or more systems. You should stop your car when it is safe and contact a breakdown service. 

Reasons for the check engine light 

The Engine Management Light and Engine Control Unit cover a variety of sensors all over the vehicle. This makes identifying the problem difficult. Here are some common causes of the Check Engine Manage Light: 

  • Problem with the catalytic converter — The catalytic converter turns harmful carbon monoxide into carbon dioxide, but the system can sometimes become clogged. You can help prevent this by taking the car on longer journeys and having it serviced regularly. A failure with this system will increase your emissions level, causing the check engine light to illuminate. 
  • EGR valve failure — The Exhaust Gas Recirculation valve controls the amount of nitrogen oxide in the engine, helping to improve the car's efficiency. Exhaust gases are redirected back through the engine's cylinders, which are used again in combustion. The valve can become stuck open or closed by a build-up of particles, causing your check engine light to be illuminating. It's recommended that a qualified mechanic clean the valve for you. Find out how much an EGR valve replacement costs.
  • Faulty spark plugs — Spark plugs ignite the fuel in the combustion chamber. If these were to fail, you would notice a decrease in your engine’s performance and increased stalling. Spark plugs should be changed regularly and per your car’s manual.
  • Fuel Injector problems — The fuel injector moderates the amount of fuel entering your vehicle's combustion chamber. If it becomes clogged, it can result in lower performance. Our price guide can help you find out how much replacement fuel injectors cost. 
  • Loose or faulty petrol cap — Driving with your car’s petrol cap open can increase emission levels as fuel hydrocarbons leak out, and pressure can be lost. If the check engine light is illuminated, it would be a good idea to check if your petrol cap is shut or if there is any damage. A faulty cap shouldn’t be too expensive to replace.
  • Malfunctioning DPF – A Diesel Particulate Filter (DPF) is fitted to diesel cars' exhausts, removing harmful particles as exhaust gases are ejected. However, these particles can build up over time. A large buildup will trigger the Engine Control Unit to start a DPF regeneration process, which burns more fuel, burning off the extra particles. If the regeneration process fails, the check engine light will be illuminated, and you should seek the advice of a qualified mechanic.  
  • Mass Airflow Sensor malfunction — The Mass Airflow Sensor tells the Engine Control Unit how much fuel to add to the combustion chamber to match the air flowing through the engine. This ensures the vehicle runs efficiently. A failure of this sensor would mean poorer fuel economy and may cause your engine to stall. The sensor sits behind the airflow filter in the engine, which can result in incorrect readings. Have the filter replaced every 12 months to ensure it works and fits correctly.  
  • Oxygen Sensor malfunction — The oxygen sensor measures the amount of unburnt oxygen emitted through the exhaust. If this sensor fails, more fuel will be burned than necessary, decreasing your car’s fuel efficiency. 

What should you do if the check engine light comes on? 

If the check engine light comes on, note the colour of the light. If it is an orange or amber colour and you feel the car is performing as it should, you can continue your journey, but make sure you book in with a garage as soon as possible. If the check engine light is red, you should find a safe place to stop and contact a breakdown service. It is not recommended you continue your journey. 

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2. ABS Light

ABS stands for anti-locking brake system. The ABS prevents your vehicle from skidding by quickly releasing and applying the brakes on the wheel.  

If the ABS light comes on, your brakes may still work, but the ABS might not engage, which may be a problem if you need to make an emergency stop.  

If the ABS and brake system lights are on at the same time, then your vehicle is unsafe to drive. Also, if the ABS light is illuminated, you should drive carefully and book in with a qualified mechanic as soon as possible. 

Bumper is here to help with car repair costs. Split the cost of your car repair in interest-free monthly instalments. 

3. Battery Light

If the battery light on your car illuminates and stays on, this indicates there is a problem with the car’s battery. There are three reasons this could happen: 

Reason 1: Damaged battery or cables 

This is the most common reason. Over time, the terminals on the battery can erode, or the cables can become unplugged or damaged. If there is damage, the battery won’t be able to hold charge from the alternator. Your battery may need replacing. 

Reason 2: Faulty alternator 

The alternator creates the electrical charge stored in your battery. It powers the headlights, radio, heater, and electric windows. If the alternator fails, no electricity will be generated, and your car will eventually lose power and stop. 

Reason 3: Broken alternator belt 

A broken alternator belt can be a severe problem, as the belt controls not only the alternator but also the coolant pump and power steering. If the battery light stays on, the engine becomes hot, or you find it hard to steer, you may have a problem with the alternator. 

What should I do if the battery light appears? 

You should turn off unnecessary electrical systems such as the radio and headlights (if it is safe).  

If you are close to home or a garage, you can continue to drive cautiously for a short distance until your vehicle is checked by a qualified mechanic.  

If you are far from home, you should not continue to drive. If your power steering fails, you may find it difficult to drive. It’s important to note that once you turn your engine off, a damaged battery may not charge enough to turn it on again. 

4. Tyre Pressure Sensor Light

Also known as the low tyre pressure light, the Tyre Pressure Monitoring System alerts you when the pressure is low.  

Underinflated or overinflated tyres can result in tyre wear. Overinflation results in decreased traction. This will result in premature wear at the centre of the tyre.  

Underinflation will cause your car to feel sluggish, decrease fuel economy, and create excessive heat build-up. This will result in premature wear on both sides of the tyre.  

If the light stays on, check the tyre pressure using a gauge and adjust it according to your car’s manual. If the light continues, you may have a puncture. 

Pro Tip: You should have your tyres changed or repaired by a professional if this light turns on. 

5. Traction Control Light/Stability Control

The Traction Control System is activated when your car detects one or more of the wheels has lost traction. This can happen in wet or icy conditions. 

When traction is lost, the engine transfers power from the slipping wheels to the wheels with grip. If the Traction Control Light is illuminated and stays on, the system has a problem. 

In some vehicles, the light illuminates when the system is engaged and goes off when the vehicle regains traction (you can check this in your car’s manual).  

If the light is on all the time, the system will be shut down, and you should take the vehicle to be checked by a qualified mechanic. You should also take extra precautions while driving to the garage. 

6. Brake System Light

Your car’s brakes are undoubtedly its most important safety system. If the brake light comes on and stays on when the hand brake is disengaged, your brakes could have a problem. 

The most likely reason for this is low brake fluid. Using your owner’s manual for guidance, locate the brake fluid reservoir and top up, if necessary, to the correct amount. 

Make sure to use the correct fluid for your engine. This can be found in the owner’s manual. You may have a leak if the light remains on when the fluid is at the correct level.  

Press down on your brake. If it sinks slowly to the floor, check under your vehicle for any yellow liquid leaking. You may have a problem with your brake pads if there is no leak. The warning light can stay on when brake pads are significantly worn. 

Some cars have a separate light for worn brake pads that looks like this:

You should not drive further with a brake fluid leak or worn brake pads. Carefully stop in a safe place and contact a breakdown service. 

7. Oil Pressure Warning Light 

There are several reasons the Oil Pressure Warning light could be illuminated. Here are some common ones: 

Reason 1: Your oil level is low 

Oil lubricates the engine, ensures all the moving parts are working correctly, and helps the cooling and cleaning process. If the oil is not kept at the correct level, you could cause costly damage to the engine.  

Check under your car — if an oily patch is underneath, you must contact a qualified technician. 

Increase your oil level by locating the dipstick. Remove the stick and wipe it with a cloth. Once wiped, replace the stick and pull it out again. You will be able to see the level of oil.  

If you’re unsure how to locate the dipstick or what the correct oil level should be, this can be found in your car’s manual. 

Reason 2: Your oil pump needs to be replaced 

If the oil pump isn’t working, the pressure will drop. This makes it hard for the oil to lubricate the moving parts in your engine, which may result in the engine making a loud noise while running.  

Check your oil level. If it is fine and there is no sign of a leak, the light may indicate a faulty pump. You should not continue to drive with a faulty pump — this could cause a lot of damage to your engine. 

Reason 3: You have a faulty sensor 

If your oil level is fine, there is no sign of a leak, and your car sounds and runs normally, it could be a faulty sensor. It is not recommended that you drive your vehicle. You should contact a breakdown service. 

8. Engine Temperature Warning Light 

The Engine Temperature Warning light indicates your engine is overheating. You should stop when it is safe and check the coolant levels under the bonnet. Be careful when doing so, as the bonnet could be hot.  

If you’re unsure how to locate the coolant tank, consult your car’s manual.  

If necessary, top up the coolant and wait at least 30 minutes for your engine to cool before continuing your journey. 

Find out what to do when your engine overheats with our guide. 

9. Fuel Indicator Light

The fuel indicator light means your car is low on fuel, and you should fill your tank as soon as possible. 

Can I drive with the fuel indicator light on? 

It is not recommended you drive far with the fuel light on.  

You should keep your tank around a quarter full at least to keep the fuel pump lubricated. If the fuel pump is continuously unlubricated for extended periods of time, this can significantly reduce its life span and make it expensive to replace. 

How many miles can I go with the fuel indicator light on? 

You may have to drive with the fuel indicator light on if you're far from your nearest garage. 

How many miles you can travel differs greatly between car makes and models, and other variables such as tyre pressure, gear choice, and the road surface can have a big effect.  

Here is a rough guide for popular models taken from the RAC:

Car Miles left
Audi A3 43 miles
BMW 3 Series 44 miles
Ford Fiesta 37 miles
Ford Focus 41 miles
Mini Cooper 44 miles
Nissan Qashqai 43 miles
Vauxhall Astra 30 miles
Vauxhall Corsa 36 miles
Volkswagen Golf 44 miles
Volkswagen Polo 42 miles

Pro Tip: The arrow next to the light indicates which side of the vehicle your fuel cap is located. 

10. Airbag and Seatbelt Light 

Common reasons for the airbag and seatbelt warning light illuminating are: 

Interference with seatbelt sensor 

If dirt has become stuck in the seatbelt catch, this can cause the seatbelt to not lock properly or cause the computer to think the seatbelt is not fastened. 

Damaged wires under seat 

The wires under the driver or passenger’s seat can be damaged by items being stored or trapped under them. 

Damaged clock spring 

The car’s clock spring allows the steering wheel to turn whilst maintaining the connection between the electrical system, horn, and airbag.  

If the clock spring is damaged, the airbag and seatbelt light may illuminate. 

Car has already been in an accident 

The car may have been in a minor accident that wasn’t big enough to trigger the airbag but triggered the warning light. In this case, the light would need resetting. 

11. Doors open reminder

The doors open reminder warning light is pretty self-explanatory. It appears if one of your doors isn’t completely shut. If it appears, stop the car and make sure all your doors are closed.  

There’s also a boot-open reminder light. Likewise, if this light appears, stop when safe and close the boot. 

12. Glow plug warning (Diesels only)

The glow plug is part of a diesel engine and heats up the combustion chambers before starting the car. This allows the fuel to create a force that turns the wheels.  

Glow plug warning lights usually illuminate before you start the car. If they appear while running, it indicates that something is wrong with the plugs or the computer that controls them. 

In any case, you should visit the garage and have a professional look at the issue. 

13. Limited power warning light (Hybrid and EV cars only)

Though tortoises look friendly, this warning light isn’t a good sign. The limited power warning light means your vehicle is running on a small amount of power and will need to be charged soon. When the power runs low, hybrid cars will start running on their alternative power sources. However, if you have low petrol or a completely electric vehicle, you need to get to a charging point as soon as possible.  

Dashboard warning lights: The bottom line 

Your dashboard warning lights aren’t just for decoration. From low fuel to engine problems, your car’s lights have appeared for plenty of reasons. Hopefully, this car warning lights guide has helped you discover what’s wrong with your vehicle.  

Bookmark this page so you can troubleshoot future dashboard warning light queries.  

Speak to an expert 

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