Every warning light requires you, as the driver, to take some sort of action. Depending on the problem, you might feel a change in how the car drives and possibly need to start looking for a safe place to stop. You should at least slow down to a safe speed, if necessary.
Many modern cars with a digital driver’s display show a message giving advice on what you should do when a warning light comes on. The severity of the problem is usually indicated by the colour of the warning light. A yellow light means there’s an issue that needs sorting out as soon as possible, but the car isn’t about to grind to a halt. Typical yellow lights include the low fuel light and the low tyre pressure warning. You should reduce your speed if necessary and start looking for a fuel station.
An amber or orange light means there’s a bigger problem. Again, the car isn’t about to grind to a halt but the engine may go into a low-power mode that makes the car move more slowly to prevent serious damage. Typical orange warnings include the engine management light and low oil level light.
A red light means there’s a serious problem that could affect your ability to drive safely. You should stop in the first safe place you can find, then call a breakdown service and have the car taken to a garage to be fixed. Typical red lights include the ABS (anti-lock brake system) failure warning and a triangular symbol that simply means ‘stop’.