What are the reasons for the engine malfunction indicator light to illuminate?
2 Answers
Reasons for the engine malfunction indicator light to illuminate include: 1. Sensor issues: Sensors such as coolant temperature, crankshaft position, air flow, intake air temperature, and oxygen sensors may be damaged or have poor connections, preventing the vehicle's ECU from accurately obtaining engine data, which triggers the engine malfunction light; 2. Poor engine maintenance; 3. The owner fails to add engine oil as required, leading to engine wear over time; 4. A dirty air filter that is not cleaned regularly can affect the vehicle's air intake, potentially causing blockages over time; 5. Turbocharger damage, which may also be accompanied by symptoms such as oil leaks and high oil consumption.
Last time I encountered this situation, I specifically went to the repair shop to ask the mechanic. He said that when the engine warning light comes on, it really shouldn't be ignored. There are several common reasons: sensor issues, such as a faulty oxygen sensor—if it monitors emission data inaccurately, the light will come on; or the catalytic converter might be clogged, causing excessive emissions; it could also be due to aging spark plugs failing to ignite properly, or fuel system problems like clogged fuel injectors leading to insufficient fuel supply. Additionally, minor issues like a dirty mass airflow sensor affecting air intake or a loose fuel cap causing fuel vapor leakage can also trigger the warning. I think the most important thing is not to continue driving, especially if the light comes on while on the highway—slow down and pull over immediately. Using a diagnostic scanner to check the trouble codes is the most reliable approach.
