Can You Drive When the Engine Malfunction Indicator Light Is On?

[DeHaley]

The engine malfunction indicator light comes in two colors: yellow and red. When the yellow light is on, you can continue driving, but when the red light is on, you must stop driving immediately. When the yellow light is on, it serves as a warning, indicating that certain system parameters in the vehicle may be outside the set range. The car can still be driven, but some functions may be restricted. When the red light is on, it means the issue is severe, and the vehicle must be stopped immediately. Turn off the engine, do not continue driving, and check for the source of the problem. There are seven main reasons why the engine malfunction light may illuminate: Sensor failure: This includes sensors such as the coolant temperature sensor, crankshaft position sensor, mass airflow sensor, intake air temperature sensor, and oxygen sensor. If these sensors are damaged, have poor connections, or lose signal, the ECU cannot accurately obtain engine data, triggering the malfunction light. Fuel or oil quality issues: If you do not use the fuel or oil specified by the manufacturer, it may cause engine wear and trigger the malfunction light. Poor combustion of the air-fuel mixture: This can lead to engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the malfunction light will illuminate as a warning. Causes include faulty spark plugs, ignition coils, fuel pump issues, or clogged fuel lines. Turbocharger problems: Issues with the intake boost system or turbocharger can also trigger the malfunction light. The most common issue is turbocharger damage, often accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Intake problems: If the car's air intake is obstructed, it may lead to engine pipe blockages, potentially triggering the malfunction light. A dirty or uncleaned air filter can cause intake issues. Exhaust problems: Exhaust system faults, such as issues with the rear oxygen sensor, catalytic converter, or exhaust camshaft and bearings, can also trigger the malfunction light. The catalytic converter is the most common culprit, especially when using leaded gasoline, improper oil additives, physical damage, or fuel system issues. Anti-theft system malfunction: If the car's electronic anti-theft system fails or the anti-theft controller does not match the engine ECU, the engine may not function properly, and the malfunction light will illuminate. If the engine malfunction light comes on, follow these steps: First, check whether the engine is running normally. If there are issues like shaking or black smoke, avoid restarting the engine. Never restart the engine if the red light is on. If the engine can start, turn it off for 5-10 minutes, then press the start button without stepping on the brake, or turn the key halfway to the 'ON' position without pressing the clutch. The car will perform a self-check, and after 5-10 seconds, check if the malfunction light turns off. If the light remains on, visit a service center as soon as possible. Technicians can use a diagnostic tool to read the trouble codes, identify the issue, and perform targeted repairs.