What Causes the Engine Malfunction Indicator Light to Stay On in a Car?
3 Answers
Reasons why the engine malfunction indicator light stays on in a car: 1. Sensor issues; 2. Poor engine combustion state; 3. Poor fuel quality; 4. Poor engine combustion state. Hazards of the engine malfunction indicator light being on: 1. Deterioration of vehicle exhaust emissions, polluting the environment; 2. Increased fuel consumption; 3. Rising combustion chamber temperature, accelerated wear, leading to engine damage; 4. Increased engine noise affecting driving. Solutions for the engine malfunction indicator light being on: 1. Clean the engine with a cleaning agent; 2. Use higher-grade gasoline; 3. Improve fuel quality.
I've been driving for fifteen years, and that engine malfunction light coming on is actually quite common. It could be a sensor issue, like the oxygen sensor that monitors exhaust gases—getting old or dirty can cause it to send false signals. There might also be a problem with the fuel system, such as clogged fuel injectors or insufficient fuel pump pressure, leading to uneven fuel combustion in the engine. Faults in the electronic control unit (ECU) are also frequent, like poor wiring connections or a damaged circuit board. These minor issues may not be obvious at first, but over time they can cause a sharp increase in fuel consumption or a drop in power. It's best not to delay—take it to a proper repair shop and connect it to a diagnostic scanner to read the trouble codes and see exactly what's triggering the alert. Regular maintenance and using good-quality fuel can prevent many of these problems.
I enjoy fixing my own car for fun. Whenever the engine malfunction light comes on, I pull out my OBD scanner to check the trouble codes. The most common culprits are sensors, like a dirty mass airflow sensor in the intake pipe or oxidized contacts. The ignition system can also fail—spark plugs might be eroded or coil insulation damaged, causing signal irregularities. Fuel system issues, like incorrect tuning or an imbalanced air-fuel mixture, can trigger the light too. Last time my light came on, it turned out the crankshaft position sensor cable was frayed; wrapping it with tape fixed the problem. If I can't solve it myself, I take the data to a mechanic for detailed analysis to avoid prolonged delays.
