Car Dashboard Warning Lights - what do they mean?
Modern cars are filled with electronics and packed with sensors to monitor both how your vehicle is behaving and to make our motoring life easier.
But when something does go wrong, it can be a difficult task trying to work out exactly what that warning light flashing away on your dashboard is trying to tell you.
It’s important to know what the car dashboard warning lights actually mean, though, not least because they can pre-empt a car breakdown or full-on failure, potentially saving you from an expensive repair bill and meaning you stay safer on the road.
Here are the most important warning lights you should watch out for:
Brake system / brake fluid warning light
Your vehicle’s brakes are arguably the most important feature on your car, so if there’s a warning light flashing on your dash highlighting there’s something wrong with the braking system, it’s best to get it checked out right away.
It could be signalling a low brake fluid level, that your brake pads are worn or that there’s a fault with the ABS anti-lock braking system. Either way, book your car in to a reputable garage to have the potential issue looked over, and if necessary, repaired.
ECU / engine warning light
If your engine warning light is illuminated, often it’ll be accompanied by some unusual symptoms – these could include a lack of power, as the car has gone into ‘safe’ mode to protect itself; an intermittent stuttering as you press the accelerator, caused by a misfire; or another fault which could alter the normal response from the engine.
Sometimes this can be down to something as small as a faulty electrical sensor, although sometimes it can be a larger mechanical issue. If your car’s engine warning light is showing, get a professional mechanic to look over it straight away, as driving around any longer could cause further, and potentially irreparable damage.
Airbag warning light
The invention of the airbag was a major step forward in vehicle occupant safety, so if your car’s isn’t working properly, get it seen to.
A faulty airbag potentially won’t go off in a crash, meaning you and your passengers won’t be as well protected from any potential injuries. The other possibility is that your vehicle’s airbag could deploy when you least expect it, giving you a nasty shock – or even actually causing an injury – and an expensive fix to put right.
Power steering / EPAS warning light
If your car’s power steering warning light – often known as the EPAS light – is illuminated, it means there could be something wrong with the steering system.
If the system fails, the steering could go heavy, meaning more effort will be needed to make the car change direction. This can be an annoyance at low speed when you’re trying to manoeuvre, but a real risk at higher motorway speeds if you need to make a sudden lane change to avoid an obstacle.
DPF / Diesel particulate filter warning light
Most modern diesel vehicles are fitted with a diesel particulate filter, which removes harmful soot from the exhaust gases to reduce emissions.
If this is faulty it’ll trigger a warning light and could not only mean you’re releasing a toxic cloud of black smoke every time you press the accelerator, but that you could be causing damage to your engine. Get this checked out straight away as DPFs can become blocked and can be expensive to replace.
Coolant warning light
Without any coolant, your car’s engine would get so hot it’d effectively ‘weld’ itself together. If you see the coolant light show up on your dashboard, it could mean coolant levels are running low, so check the gauge on the side of the coolant tank under the bonnet and top up if necessary.
In conjunction with a temperature gauge reading well into the red, it could mean your engine is overheating. This is either the sign of a larger problem – like a head gasket failure – or symptomatic of something less major, like a leak in the system somewhere, meaning you’re engine has run low on coolant and got too hot. Get it seen to as soon as possible to avoid a potentially expensive repair bill.
Oil warning light
Just like your car’s water or coolant warning light, you might see an oil warning light flash up if oil temperature gets too high, the level is low or oil pressure too low. It’s the latter two you want to avoid at all costs.
Oil is what lubricates your engine, with the oil pump used to spray the fluid to all corners of your engine. If temperatures get too high, or even worse, level is low or oil pressure drops, the effectiveness of the lubrication can be reduced or lost all together
The result? Expensive engine damage, so if you see this warning sign, stop and phone a professional right away.
Tyre pressure monitor warning light
Once the preserve of high-end, super-expensive luxury saloons, many more cars are fitted with tyre pressure monitoring systems today.
These systems can sense a deviation away from normal tyre pressures, signifying a puncture. Generally, the device will flash a warning light on the dashboard, highlighting you should take a look at your car’s rubber.
Battery charge warning light
You should see your battery charge warning light when you first turn your car on, but if it doesn’t go out a few seconds after the engine starts, there could be a problem with your car’s electrical system.
This could be to do with a faulty alternator, faulty battery, a bad connection or damaged cabling somewhere in the engine bay. If your car isn’t charging its battery when moving (the job of the alternator), then you could eventually run out of electrical power and grind to a halt.
At worst, the light could be on due to an alternator drive belt braking. Other systems also use this belt – such as the engine coolant pump, or power steering – so the affects of a failure here could be compounded.
Warning light woes
It’s not a game of connect four or warning light bingo – if your car’s dashboard is lit up like a Christmas tree, or even if there’s one, small blinking light on there, it’s important to get it checked out.
It could be something as minor as a faulty sensor or a broken wire, but it could be something more serious that, if left unchecked, will cause lasting and expensive damage to your vehicle.
Regular servicing and maintenance can help protect your vehicle from firing off a fault, so keep a close eye on your car and its warning lights to save you money and avoid those expensive garage bills.
Have you got a warning light illuminated, or have you previously had a problem with your car signified by a telltale sign on the dashboard? How did you go about fixing it and what advice would you give to other motorists with a dash full of LED warnings?
Let us know on our RAC Facebook page.