Green or blue — information only
Low fuel
Only the reserve is left in the tank. On most cars that is five to ten litres — the exact figure is in the handbook, and it differs even between neighbouring models.
These lamps are not about a fault: they say a system is switched on, or remind you of something simple to do.
What to do now
- Refuel at the first opportunity — but without panic: the reserve is there for exactly this.
- Do not run it down to the last regularly. The fuel pump is cooled by the fuel, and constant driving on the dregs shortens its life.
- On the last of the tank the pump picks up air in corners and on hills: misfires appearing then are a consequence of an empty tank, not a fault.
Codes usually behind it
The lamp only says that something is wrong. The code says what exactly — read it with an adapter and look it up here.
What to read next
A lamp is not a diagnosis. The same symbol lights up for a dozen different reasons, and only the code stored in the car tells them apart.
How the app helps
CarScan reads the codes behind the lamp through an OBD-II adapter, explains them in plain words and puts them into a report you can show to a mechanic.