Why is the engine malfunction indicator light on?
3 Answers
There are various reasons that can cause the engine malfunction indicator light to illuminate: sensor malfunctions, spark plug issues, ignition coil problems, fuel pump failures, fuel line blockages, etc. When the engine malfunction light comes on, it can be categorized into three scenarios, each requiring a different response: 1. The car cannot start: This may be caused by a fuel pump or ignition component failure, and repair is recommended. 2. The malfunction light is on, but there are no noticeable abnormalities while driving: This might just be a sensor malfunction, and you can continue driving temporarily, but it's best to drive at low to medium speeds. 3. The engine malfunction light is on, and the vehicle can still be driven, but exhibits severe shaking, lack of acceleration power, etc.: In this case, you should not continue driving.
I've been driving for over a decade, and it's quite common for the engine warning light to come on, usually due to issues with the exhaust system or sensors. For example, if the oxygen sensor gets dirty or fails, it might falsely indicate that the emissions aren't up to standard, triggering the warning light. Another possibility is a clogged catalytic converter affecting emissions. If these minor issues aren't addressed promptly, fuel consumption can spike, and the engine is more prone to overheating and damage. From my experience, regular checks on the air filter and fuel quality, along with scheduled maintenance, can help prevent such problems. Sometimes, computer malfunctions or aging ignition coils can also trigger the warning light. Don't panic—the best approach is to visit a shop and use a diagnostic tool to read the trouble codes.
From a daily maintenance perspective, the illumination of the warning light is mostly due to abnormalities detected by the OBD-II system, such as an inaccurate air flow meter or turbulent airflow causing an imbalance in the air-fuel mixture. A clogged fuel injector could also be the culprit, as poor fuel spray leads to incomplete combustion. These system faults are prone to surface during frequent starts or in traffic jams. Ignoring them can accelerate spark plug wear and worsen emissions. I must remind you to safely pull over first to avoid affecting driving stability. Early diagnosis with a multimeter to check voltage or inspect plug tightness can prevent minor issues from escalating.
