Car Warning Lights - What Do They Mean?

The cause: If this light doesn't go out a few seconds after starting the engine, there could be a fault in your alternator, battery or electrical system. This means that your car isn't charging itself when driving, which could cause the battery to drain and the engine to eventually stop.

The solution: If this light comes on, you should turn off anything non-essential that uses the battery (e.g. heating, air conditioning, radio, charging devices, sat navs and heated seats). Don’t stop and turn off your engine straight away because your car may not start again. Instead, wait until you’re somewhere safe. You can then visit any Halfords Autocentre for a Free Battery Health Check.

The cause: If this light appears while you're driving, then you’ve probably left your handbrake on. If your handbrake is off, but the light is still on, it may mean that you’re low on brake fluid or there’s a serious problem with your hydraulic brake system.

The solution: If you notice a difference in your brakes – for example, if they feel spongy or the pedal sinks to the floor – then pull over and call your breakdown service immediately. If the brakes feel normal, it's still recommended that you book in for a Free Brake Check at your local Halfords Autocentre.

The cause: You or a passenger are not wearing a seatbelt while the vehicle is in motion.

The solution: This is a simple problem to resolve, but also one of the most important. If this light comes on, it essentially means someone in the car isn’t wearing a seatbelt. Please remember that all passengers, whether they're sitting in the front or the back, are required to wear a seatbelt by law.

The cause: The most common reason for this indicator to appear is a lack of power steering fluid, but there also may be a more serious problem with the system.

The solution: Pull over, switch the engine off and check your power steering fluid levels. If the light remains illuminated, seek assistance as it may not be safe to continue driving.

If you've recently disconnected the battery, you'll need to reset the steering system. Turn your steering wheel fully left and then fully right before driving slowly for a short distance.

For added peace of mind, you can also take advantage of our Free Steering Check, which is available at our Halfords Autocentres.

The cause: Your coolant level is low. Without coolant, the car will get too hot to function and this could cause damage to the engine, which can be very expensive to repair.

The solution: First, pull over to allow the engine to cool down. Next, check the coolant level in the tank under the bonnet. Be very careful when opening the lid on the coolant tank because you could be scalded by escaping steam if the engine is still hot.

If the coolant level is fine, but the light comes back on, it could mean you have a leaky radiator or a more serious problem such as a blown head gasket. If this is the case, you need to get your car looked at straight away.

The cause: Either your boot, bonnet or one of the car doors hasn’t been shut properly.

The solution: Pull over and make sure that all your doors are firmly shut. If you have children in the back seats, it's a good idea to switch on the child safety locks to ensure they don't open the doors when the car is in motion.

The cause: There's a fault with one or more of your airbags.

The solution: If there’s a fault with your airbag, you should get this looked at by a mechanic straight away. If you don’t and then get into an accident, the airbag may not activate, and this could leave you and your passengers without protection. Alternatively, it could be activated when you least expect it, causing injury.

The cause: A sensor has detected a problem with your engine. This light could indicate a number of things, from simple issues such as a fuel cap not being fastened correctly to wider problems with the engine or emissions system like a failed catalytic converter.

The solution: Even if your vehicle is not experiencing any other symptoms, it's best to get this checked with a diagnostic machine at a trusted garage to determine the problem. Our full Diagnostic Check is a great option as our experts will be able to identify any issues or faults and advise on repairs.

The cause: The tyre-pressure monitoring system has detected a drop in pressure.

The solution: You could have a puncture in one of your tyres, or they may just need inflating. Your tyre pressures can affect your braking distance and handling, so it's best to stop and check your tyres and pump them up if necessary. If you notice a puncture, change the wheel or use sealant to stop the leak. Then visit your nearest Autocentre to get it repaired. We also offer a Free Tyre Check for added peace of mind. See our guide on tyre pressure warning lights here.

The cause: Your glow plugs, which are heating elements that help start your engine, are faulty.

The solution: It's normal for the warning light to appear for a second or two on start. However, if it stays on longer, visit your local Halfords Autocentre for a diagnostic check as you may require a replacement.

The cause: There’s a fault in your ABS braking system, which helps your car come to a stop in emergencies.

The solution: If the ABS braking system is working, you should feel the brake pedal pulsing when you brake hard. If it's not doing this, you need to get your car checked out as soon as possible, as your emergency braking may be affected.

If the ABS indicator is on and the brake warning light is showing, it could mean there is something seriously wrong with your brakes. We recommend booking in for a Free Brake Check at your local Halfords Autocentre where an expert can assess the system.

The cause: This will usually mean that you’re very close to running out of charge, and depending on your vehicle, it may stop.

The solution: Your car will start to use up its stored supply of petrol or diesel but, if you have a plug-in hybrid, you may want to plug into an electrical charging point at your nearest charging station. Make sure you monitor the charge gauge to see how much power is remaining during your journey. If you're concerned about your Hybrid vehicle, visit your nearest Halfords Garage where our experts will be able to assist you.