What does it mean when the car's warning light comes on?
3 Answers
The reasons for the car's warning light coming on are: 1. Poor engine combustion state; 2. Use of low-quality fuel; 3. Carbon deposits in the engine cylinders. To ensure the car engine operates in good condition and maintains a normal service life, an oxygen sensor is installed in the engine during design to monitor the combustion state. If the engine's combustion state is poor, it will increase fuel consumption and wear, and also pollute the environment. The car engine has certain requirements for fuel quality, and nowadays, the requirements for fuel quality are increasingly higher. If the fuel added is of poor quality, the engine warning light will come on. As the operating time increases, carbon deposits will form inside the engine. These carbon deposits can cause changes in the engine's design parameters, making the engine unstable and accumulating heat. This heat can lead to irregular ignition in the engine, resulting in engine knocking.
Last time I was driving on the highway, the warning light suddenly came on, which gave me a scare. Common dashboard lights include the engine light, oil light, and battery light. If the engine light is yellow, it might be a sensor error or fuel quality issue, but if it's red, it's more serious—possibly indicating cylinder misfire or catalytic converter blockage. If the oil light flashes, you should pull over immediately and check the dipstick—it could be an oil leak or oil pump problem. The battery light usually means the alternator is faulty or there's poor wiring contact. I recommend using an OBD scanner to read the trouble code first, so you know what you're dealing with. Like me, if you often drive long distances, it's good to keep a small scanner in the car to avoid being overcharged by repair shops. The key is to pay attention to the light color—yellow means you can still make it to a repair shop, but red means you must pull over and shut off the engine right away.
I've repaired quite a few cars, and the issue with warning lights depends on the icon type. The engine light usually indicates incomplete combustion, commonly caused by low-quality fuel, aging spark plugs, or a damp intake sensor after heavy rain. The brake system light may mean worn brake pads or low fluid levels. If the coolant temperature light comes on, you must stop immediately—it could be a coolant leak or a faulty cooling fan. Dashboard designs are quite user-friendly, with yellow lights as warnings and red lights indicating danger. Car owners can troubleshoot minor issues themselves: check tire pressure, ensure the fuel cap is tight, and see if the engine oil has turned black. But when it comes to electrical or control system faults, don’t tinker blindly. Last time, someone tried removing the throttle body themselves and ended up breaking the connector, costing an extra two thousand yuan.
