What Does It Mean When the Engine Fault Light Comes On When Starting the Car?
2 Answers
When the engine fault light comes on while starting the car, it could be due to the following reasons: 1. Sensor issues: Sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors may be damaged, have poor contact, or experience signal interruption. In such cases, the car's ECU cannot accurately obtain engine data, leading to the illumination of the engine fault light. 2. Maintenance issues: Poor engine maintenance is the most common cause of the engine fault light. Failure to perform regular maintenance, combined with poor driving habits, increases the burden on the engine. 3. Fuel and oil quality issues: Manufacturers usually recommend specific grades of fuel and types of engine oil. Not adhering to these recommendations can cause engine wear over time, eventually triggering the fault light. 4. Poor combustion of the air-fuel mixture: Faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can lead to poor combustion, resulting in engine carbon buildup or knocking. These issues are detected by the engine's oxygen sensor and reported to the ECU, which then illuminates the fault light as a warning. 5. Air intake issues: Proper air intake is essential for engine combustion. A dirty or clogged air filter can restrict airflow, leading to potential blockages and, in severe cases, triggering the engine fault light.
Last time I started my car, the check engine light also came on. It's most likely an issue with the sensors or fuel delivery system. The probable culprits are a faulty oxygen sensor, bad mass airflow sensor, or poor-quality gasoline causing incomplete combustion. Carbon buildup clogging the throttle body can also trigger the warning light. A friend of mine once had this happen because his air filter was too dirty - the ECU detected insufficient airflow during startup and triggered the alarm. If the light comes on during cold starts and occasionally disappears after restarting, but stays lit long-term, you should definitely take it seriously as it could affect the catalytic converter or even cause engine seizure. I recommend first checking if the fuel cap is tightened properly. If that doesn't help, go to a repair shop to read the trouble codes. Whatever you do, don't keep driving it forcefully - you might end up spending big money on engine repairs.
