Modern cars are fitted with numerous warning lights that give the driver key information. There used to be only a handful, but today there are many more, which can be confusing. Below we explain what the most common symbols mean and when you should pay particular attention to them.
Types of warning lights on the instrument panel
Warning lights on the instrument panel come in three basic colours: red, amber (or yellow) and green (or blue). They work much like a traffic light:
- Red lights warn of a serious problem: stop the vehicle as soon as it is safe to do so and have the fault fixed before driving on.
- Amber or yellow lights indicate less urgent problems, such as a fault or a system that needs checking, although some are purely informational.
- Green and blue lights simply tell you that a function is active, such as the headlights being on, and require no action from the driver.
How do you tell what a warning light means?
The colour of the light shows how serious the problem is, while the symbol tells you which system or part of the car it refers to. Below are the most common lights.
Red warning lights
Red lights indicate faults or situations that need immediate attention. They include:
- Braking system: an exclamation mark inside a circle, between brackets.
- Power steering: a steering wheel with an exclamation mark.
- Airbags: a seated person with an inflated airbag in front of them.
- Battery charging problem: a battery symbol.
- Low oil pressure: an oil can.
- High coolant temperature: a thermometer over waves.
Red lights can also show simpler things, such as a door left open, an unfastened seat belt or the handbrake still on. For a red fault warning, react immediately and stop the vehicle.
Amber or yellow warning lights
Amber lights indicate significant problems, but you can usually still drive. You should, however, visit a workshop as soon as possible. Most commonly they indicate:
- Engine warning: an engine outline, sometimes with the words check engine.
- ESP system: a skidding car, sometimes inside a circular arrow.
- ABS system: the letters ABS inside a circle between brackets.
- Transmission problem: a gear wheel with an exclamation mark.
- Low tyre pressure: a tyre cross-section with an exclamation mark.
- Low fuel level: a fuel pump.
Green and blue indicator lights
These lights are not warnings; they simply tell you which of the vehicle’s functions are active. Typically they show:
- Indicators: two arrows, one pointing left and the other pointing right.
- Dipped headlights on: a green headlight symbol.
- Main beam on: a blue headlight symbol.
- Cruise control: a speedometer with an arrow.
A special note about the DPF
The symbol showing a rectangle with dots, or a rectangle with arrows, refers to the diesel particulate filter (DPF). When the DPF light comes on, it may mean that the filter needs to regenerate — usually a longer drive at steady speed helps. If the light does not go out, have the car checked at a workshop. Ignoring this light can lead to:
- engine problems,
- oil dilution,
- limp-home mode,
- damage to the turbocharger or the injectors.
The solution is professional DPF cleaning with a specialised machine, such as the DPF Master Flash™ Professional PLUS from XTON®, which restores the filter to up to 99% of its factory performance.
Conclusion
Red lights require an immediate reaction and stopping the vehicle. Amber lights mean the vehicle should be checked at a workshop. Green and blue lights are purely informational and show which functions are active.
If an unfamiliar light comes on, check the vehicle’s handbook or visit a workshop to avoid bigger problems.