What causes the engine indicator light on the dashboard to illuminate?
2 Answers
The engine indicator light on the dashboard may illuminate for the following main reasons: 1. The engine warning light turns on for a few seconds and then turns off after starting the vehicle. This is the car performing a self-check, which is a normal phenomenon. 2. Poor quality or substandard gasoline: Shortly after refueling, the engine warning light appears on the dashboard. This is usually caused by filling up with low-quality gasoline at non-standard gas stations, leading to incomplete combustion of the air-fuel mixture during engine operation and triggering the engine warning light. 3. Spark plug carbon buildup: Carbon deposits on spark plugs can cause poor engine performance, resulting in abnormal phenomena such as difficulty starting, unstable idling, poor acceleration, backfiring during sudden acceleration, excessive exhaust emissions, and increased fuel consumption.
I've been driving for nearly twenty years and have seen the engine light come on countless times. Common causes include aging oxygen sensors, which monitor the amount of oxygen in the exhaust—once they become inaccurate, they trigger a warning. There are also ignition system issues, such as worn spark plugs or faulty ignition coils leading to incomplete combustion. A clogged exhaust system, like a bad catalytic converter, can also turn on the light. Even a loose gas cap can trigger an alert due to fuel vapor leakage. The key is not to ignore it but also not to blindly rush into repairs: first, use an OBD2 scanner to read the trouble codes—they cost just a few dozen yuan on Taobao—then determine the issue based on the code. Simple problems can be handled yourself, like replacing a faulty sensor, but for complex issues, it's best to seek professional diagnosis at a reputable shop.
