What does it mean when a car's warning light comes on?

[SanJuniper]

Here are the possible reasons for a car's warning light to illuminate: 1. Insufficient engine oil: The engine cannot establish sufficient oil pressure, with the potential danger being inadequate oil supply from the oil pump. This prevents the oil from fully covering the engine's inner walls and forming a protective film to prevent wear. 2. Insufficient oil pump pressure: This is a hardware failure, meaning the oil pump is malfunctioning, damaged, or seized. It cannot deliver oil to other parts of the engine. If this is the cause, the vehicle should be stopped as soon as possible to prevent the engine from operating without oil lubrication, leading to dry friction. This helps avoid engine overheating, quenching, or even severe damage like connecting rod seizure. 3. Coolant temperature or level warning light: The coolant level in the engine should not decrease since the engine's cooling system is essentially sealed. In this case, it can be directly inferred that there is an issue with the cooling system.