Green or blue — information only
Cruise control
Cruise control is on or already holding speed. The symbol differs by make: a speedometer with an arrow, a car outline, or the word CRUISE.
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
- Cruise switches off by itself when you press the brake or clutch — that is not a fault.
- ⚠️ If the symbol blinks or goes out while driving, the brake light switch is the usual culprit. Code P0504 shows up alongside.
- On a slippery road it is better left off: it adds throttle exactly where you need less.
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.