Red lights require you to stop as soon as possible, yellow ones signal a fault to be checked soon, green and blue ones simply indicate active functions. The colour is the first useful clue to how serious it is.
Red lights: stop
- Oil pressure: immediate stop, risk of seizure
- Engine temperature: risk to the head gasket
- Battery: the car is not charging, limited range
- Brakes: possible leak in the circuit
- Airbag: passive safety not guaranteed
Yellow lights: check soon
- Engine (check engine) light, steady or flashing
- ABS, ESP, TPMS, DPF/FAP, AdBlue
- Flashing preheat light on diesels
Rule of thumb
A flashing yellow light is more serious than the same light steady: a flashing engine light, for example, indicates a misfire that can ruin the catalytic converter. In that case reduce speed and have the car checked immediately.
How MasterTuning helps
We read the ECU with professional tools, interpret the real fault codes and tell you what really needs repairing, without unnecessary replacements. Diagnosis, repair and software recalibration at our centres throughout Italy.
Is a warning light on? Contact us for a diagnosis or find your nearest MasterTuning centre.
