What is the reason for the engine malfunction light being on but the car can still run normally?
2 Answers
The reason for the engine malfunction light being on but the car can still run normally is that the car needs maintenance such as an oil change. The engine malfunction light on the dashboard, usually red or yellow, will not automatically disappear in most cases once it lights up, though it may disappear on its own in rare instances. This is what is referred to as the engine malfunction light. If there is a current engine system fault, it should be checked and repaired promptly. Additionally, the fault information will be stored and provided as a reference to the car maintenance supervisor during repairs to resolve the issue more quickly. To ensure the engine can continue running when a fault occurs, if the detected fault has minimal impact on the engine's operation, the computer will ignore it. However, in reality, the engine is not in good working condition under such circumstances.
Yesterday my car's check engine light came on, but it drove fine otherwise. I asked a friend who knows about car repairs, and he said this is quite common, mostly due to sensor false alarms. For example, the oxygen sensor readings could be skewed by carbon buildup, or the fuel cap might not be tightened properly, causing fuel vapor leaks and triggering the system alarm. It could also be due to unstable battery voltage, causing the ECU to misjudge the fault. My friend said if this happens right after refueling, it's likely due to poor fuel quality. However, he also reminded me that while I can keep driving, I should read the trouble codes as soon as possible, as minor issues left unattended could eventually damage the catalytic converter.
