Green or blue — information only
A door or the boot is open
One of the doors, the bonnet or the boot is not properly closed. The symbol usually shows which one.
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
- Stop and close it properly. On the move an ajar door is not only noise: in some systems it also disables an airbag.
- If every door is shut and the lamp stays on, the door switch is usually to blame — the little contact in the door frame. It sticks with dirt and water.
- A stuck switch keeps the interior light on and can flatten the battery overnight — that is the real trouble, not the lamp itself.
- Checking the switch takes a minute: open the door and press it with a finger — the interior light must go out. If it does not, the switch is to blame, not the module.
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.