means something is not working coeerctly, but without knowning what the light is for or what vehicle, that's all i can tell you
Might be the check engine light. See related questions below.
one of tyres are low pressure
Traction control system. If the light is on constantly, there is a malfunction.
Time for scheduled maintenance.
A small yellow symbol lit up on my dashboard, is it the transmission light?
oil light on when engine off
It means there is an electrical fault with the Fuel injection system.
This indicates the front brake pads are worn.
On my 95 Avalon, there was a yellow picture of a car showing that my rear lights (license plate) were out.
You can drive your car with the yellow 'service engine' light on the dashboard, but it is not recommended. This light warns you of the need to have the engine serviced.
TPMS Tire Pressure warning
does it have two yellow lines surrounding it? kinda circling it? if so that's your tire pressure light
its a rear bulb failure indicator if it comes on when brake is first depressed it is a brake light bulb if it is on when you start the car it is a ride light or park light