What does it mean when the car engine warning light comes on?

[Anthony]

There are several reasons why the car engine warning light may illuminate: 1. Sensor issues, including those related to water temperature, crankshaft position, air flow, intake temperature, oxygen sensors, etc. When sensors are damaged, have poor contact, or experience signal interruption, the car's ECU cannot accurately obtain engine data; 2. Poor engine maintenance, where the owner fails to perform regular maintenance coupled with bad driving habits, which can increase the burden on the engine's operation; 3. The fuel and engine oil used in the car have specific grades, with engine oil being categorized into semi-synthetic and fully synthetic. Manufacturers recommend certain fuel grades and oil types for use, and failure to adhere to these recommendations over time can lead to engine wear; 4. Faults in the engine's spark plugs, ignition coils, fuel pump, or fuel line blockages can all cause poor combustion of the air-fuel mixture, leading to engine carbon buildup or knocking issues. These problems are detected by the engine's oxygen sensors and reported to the ECU; 5. The engine requires air intake for combustion. If the car's air filter is dirty and not cleaned regularly, it can affect the air intake, potentially leading to blockages over time.