What does that warning light on your dashboard mean?

How it works

Dashboard lights use a colour system like traffic lights. Red means a possibly serious fault: do not set off, and if it comes on while you drive, stop where it is safe. Amber means something needs checking or maintenance soon. Green and blue lights only tell you that something is on, such as the dipped headlights or cruise control. Many lights come on for a moment when you start the car; that is a bulb check and normal.

The symbols themselves are largely shared across makes, because the international standard ISO 2575 defines the shapes and UN Regulation 121 says which ones a car must show and in which colour. That is why an oil can means oil pressure and an exclamation mark in a circle means the brakes in almost every car. The drawings here are our own simple versions of those shapes.

Example: a red battery symbol while driving means the battery is no longer being charged. The car keeps running on the battery for a while, so switch off what you can do without and drive to a garage or a safe place before it stops. Makers still differ in details, so the owner's manual is the final word for your car.