Dashboard lights mostly follow a colour pattern. Red usually means a serious fault, so stop safely. Amber or yellow usually means a fault that should be checked soon. Green or blue usually just shows a system is on.
Lights drivers ask about most
- Battery light: a charging problem. It could be the alternator, the belt or the battery, and the car may stop once the battery runs flat.
- Engine temperature: the engine is overheating. Pull over safely and switch off.
- Oil pressure: stop as soon as it is safe. Driving on can damage the engine.
- Check engine or engine management: the car has logged a fault. A scan reads the stored code, which points the check in the right direction.
- ABS or airbag: a safety system has flagged a fault and should be checked.
Your owner manual lists the exact meaning of each light for your car.
Why scanning matters
A fault code points to an area, not always to a part. Fault-finding after the scan confirms what has actually failed, so you do not pay to replace parts that were fine.