June 2021

Modern cars are packed with electronics and sensors to monitor how your vehicle is behaving. These systems are finely tuned and usually work very well, but you never know when a warning light will start to glow on the dashboard.

We all know that if we ignore the ‘low fuel’ light for too long, our near future probably involves a slightly embarrassing phone call to the rescue crew as we’re stranded by the side of the road. But for many motorists some of the less familiar warning lights somehow feel easier to ignore. After all if you pretend you can’t see it, then maybe it’s not really there.

Understanding Dashboard Symbols

Before looking at the warning lights themselves, you need to know what to do if one appears and how they might be displayed. Next time you start your car, turn the ignition on and look at them all carefully, because they'll all light up as a test. They should then all go out once you've started the engine, except for your handbrake light if it's engaged. It’s always a good idea to keep your owner’s handbook in the glove compartment for reference, just in case one of these symbols do pop up. Some newer cars have on-board computers that might tell you a bit more about the problem.

Engine Management

This could light up for a number of reasons. It could be as simple as a faulty sensor, or it could be detecting an engine or emissions problem. You might hear or feel problems with the engine's performance too - perhaps it's gone into "limpmode" with limited speed. If this light comes on, we advise you to visit your local dealership as soon as possible.

engine management light


Your brakes are really important, so if this one lights up, get it checked immediately. It could be a drop in brake fluid level, or your brake discs or pads could need replacing, it’s best to book your car in for an inspection by an expert. You don’t want to wait until you really need them to discover that there is less stopping power than you expected.

Brakes light

​Diesel Particulate Filter (DPF)

If you drive a modern Diesel car than it will be fitted with a DPF, which helps reduce harmful emissions. However, these are prone to blockages if you frequently do short journeys at low speeds. Your car will occasionally run an automatic program to clear itself out. Therefore, if it can't clear itself, the DPF light will come on, so it’s worth booking the car in to be examined

Diesel particulate filter warning light

Oil Light

Never refill your oil while your car is hot! Hopefully you regularly check your oil level, because if this light comes on then it has got lower than it should be and damage could already be occurring. You should top it up urgently, checking your handbook if you’re unsure of the correct oil or quantity to use. If the light still appears after you’ve done this you should definitely book the car in for an examination. You can always bring the oil into us at Thame Cars and we can refill it for you!

oil light


If your coolant light comes on then your coolant level has got too low and you should stop immediately in a safe place. Keep a close eye on the temperature gauge, don’t attempt to change the coolant or open the tank whilst the engine is hot as there is built up pressure in the reservoir of the coolant, seek the advice of your local garage or call for breakdown recovery.

coolant light


If you see a battery symbol come up while driving then it means that your car isn't charging it correctly. This could either be down to a failing battery, or it could even be that the alternator isn't charging it properly. Get both checked at a garage.

Battery light

Tyre Pressure Warning

More cars are being fitted with tyre pressure monitors, which flash up a warning if one of your tyres loses pressure. If this light comes on, check the pressures in all your tyres by stopping at the nearest petrol station. You can check your correct tyre pressure in your handbook, tyre pressures can vary depending on load, so it’s best to check with your dealer. Most modern cars will tell you which tyre has low pressure, whilst filling up the low tyre it’s worth checking all the others. Keep an eye out for the tyres losing pressure frequently as it could be a sign of a puncture, if you’re unsure just pop into your local dealership and they’ll check it out.

Tyre Pressure Warning Light

ABS (Anti-Lock Braking System)

If this light comes on, your brakes will still be working however, ABS prevents your car from skidding in an emergency breaking situation. So if this light comes on there is a fault, therefore it should be checked immediately to ensure you have maximum vehicle control and a safe stopping distance.

ABS light

Traction Control System

During poor weather conditions such as winter periods or in rainy/snowy conditions it may flash up occasionally. It helps the driver maintain control and stability when the vehicle loses grip causing the wheels to spin. The TCS shifts the power from the wheels that are slipping to the wheels that have grip. If the light stays on constantly you should seek professional advice from your local dealership.

Traction control

Sod's law says that a warning light will come on at the most inconvenient time. Nonetheless never forget that it's come on for a reason and usually means that something is wrong. So if you see a warning light, have a flick through your owner's manual and seek urgent advice if you're not sure what's wrong. Always query a warning light on a car you're test driving.

At Thame Cars, we're always happy to introduce you to all aspects of your car, including your dashboard symbols, so pop in if we can help.